feat: drop table location mapping support (#8458)

* feat: drop table location mapping support

Disable external metadata locations for S3 Tables and remove the table location
mapping index entirely. Table metadata must live under the table bucket paths,
so lookups no longer use mapping directories.

Changes:
- Remove mapping lookup and cache from bucket path resolution
- Reject metadataLocation in CreateTable and UpdateTable
- Remove mapping helpers and tests

* compile

* refactor

* fix: accept metadataLocation in S3 Tables API requests

We removed the external table location mapping feature, but still need to
accept and store metadataLocation values from clients like Trino. The mapping
feature was an internal implementation detail that mapped external buckets to
internal table paths. The metadataLocation field itself is part of the S3 Tables
API and should be preserved.

* fmt

* fix: handle MetadataLocation in UpdateTable requests

Mirror handleCreateTable behavior by updating metadata.MetadataLocation
when req.MetadataLocation is provided in UpdateTable requests. This ensures
table metadata location can be updated, not just set during creation.

weed/s3api/auth_proxy_integration_test.go

@@ -46,68 +46,68 @@ func TestReverseProxySignatureVerification(t *testing.T) {
 }`
 
 	tests := []struct {
-		name             string
-		externalUrl      string // s3.externalUrl config for the backend
-		clientScheme     string // scheme the client uses for signing
-		clientHost       string // host the client signs against
-		proxyForwardsHost bool  // whether proxy sets X-Forwarded-Host
-		expectSuccess    bool
+		name              string
+		externalUrl       string // s3.externalUrl config for the backend
+		clientScheme      string // scheme the client uses for signing
+		clientHost        string // host the client signs against
+		proxyForwardsHost bool   // whether proxy sets X-Forwarded-Host
+		expectSuccess     bool
 	}{
 		{
-			name:             "non-standard port, externalUrl matches proxy address",
-			externalUrl:      "", // filled dynamically with proxy address
-			clientScheme:     "http",
-			clientHost:       "", // filled dynamically
+			name:              "non-standard port, externalUrl matches proxy address",
+			externalUrl:       "", // filled dynamically with proxy address
+			clientScheme:      "http",
+			clientHost:        "", // filled dynamically
 			proxyForwardsHost: true,
-			expectSuccess:    true,
+			expectSuccess:     true,
 		},
 		{
-			name:             "externalUrl with non-standard port, client signs against external host",
-			externalUrl:      "http://api.example.com:9000",
-			clientScheme:     "http",
-			clientHost:       "api.example.com:9000",
+			name:              "externalUrl with non-standard port, client signs against external host",
+			externalUrl:       "http://api.example.com:9000",
+			clientScheme:      "http",
+			clientHost:        "api.example.com:9000",
 			proxyForwardsHost: true,
-			expectSuccess:    true,
+			expectSuccess:     true,
 		},
 		{
-			name:             "externalUrl with HTTPS default port stripped, client signs without port",
-			externalUrl:      "https://api.example.com:443",
-			clientScheme:     "https",
-			clientHost:       "api.example.com",
+			name:              "externalUrl with HTTPS default port stripped, client signs without port",
+			externalUrl:       "https://api.example.com:443",
+			clientScheme:      "https",
+			clientHost:        "api.example.com",
 			proxyForwardsHost: true,
-			expectSuccess:    true,
+			expectSuccess:     true,
 		},
 		{
-			name:             "externalUrl with HTTP default port stripped, client signs without port",
-			externalUrl:      "http://api.example.com:80",
-			clientScheme:     "http",
-			clientHost:       "api.example.com",
+			name:              "externalUrl with HTTP default port stripped, client signs without port",
+			externalUrl:       "http://api.example.com:80",
+			clientScheme:      "http",
+			clientHost:        "api.example.com",
 			proxyForwardsHost: true,
-			expectSuccess:    true,
+			expectSuccess:     true,
 		},
 		{
-			name:             "proxy forwards X-Forwarded-Host correctly, no externalUrl needed",
-			externalUrl:      "",
-			clientScheme:     "http",
-			clientHost:       "api.example.com:9000",
+			name:              "proxy forwards X-Forwarded-Host correctly, no externalUrl needed",
+			externalUrl:       "",
+			clientScheme:      "http",
+			clientHost:        "api.example.com:9000",
 			proxyForwardsHost: true,
-			expectSuccess:    true,
+			expectSuccess:     true,
 		},
 		{
-			name:             "proxy without X-Forwarded-Host, no externalUrl: host mismatch",
-			externalUrl:      "",
-			clientScheme:     "http",
-			clientHost:       "api.example.com:9000",
+			name:              "proxy without X-Forwarded-Host, no externalUrl: host mismatch",
+			externalUrl:       "",
+			clientScheme:      "http",
+			clientHost:        "api.example.com:9000",
 			proxyForwardsHost: false,
-			expectSuccess:    false,
+			expectSuccess:     false,
 		},
 		{
-			name:             "proxy without X-Forwarded-Host, externalUrl saves the day",
-			externalUrl:      "http://api.example.com:9000",
-			clientScheme:     "http",
-			clientHost:       "api.example.com:9000",
+			name:              "proxy without X-Forwarded-Host, externalUrl saves the day",
+			externalUrl:       "http://api.example.com:9000",
+			clientScheme:      "http",
+			clientHost:        "api.example.com:9000",
 			proxyForwardsHost: false,
-			expectSuccess:    true,
+			expectSuccess:     true,
 		},
 	}