feat(sources/mssql): add app name to MSSQL (#1620)

## Description --- Add auditable application name to mssql sources. Query the db with: ``` SELECT session_id, program_name FROM sys.dm_exec_sessions; ``` ## PR Checklist --- > Thank you for opening a Pull Request! Before submitting your PR, there are a > few things you can do to make sure it goes smoothly: - [ ] Make sure you reviewed [CONTRIBUTING.md](https://github.com/googleapis/genai-toolbox/blob/main/CONTRIBUTING.md) - [ ] Make sure to open an issue as a [bug/issue](https://github.com/googleapis/genai-toolbox/issues/new/choose) before writing your code! That way we can discuss the change, evaluate designs, and agree on the general idea - [ ] Ensure the tests and linter pass - [ ] Code coverage does not decrease (if any source code was changed) - [ ] Appropriate docs were updated (if necessary) - [ ] Make sure to add `!` if this involve a breaking change 🛠️ Fixes #<issue_number_goes_here>

Author: averikitsch

internal/sources/cloudsqlmssql/cloud_sql_mssql.go

@@ -111,20 +111,25 @@ func initCloudSQLMssqlConnection(ctx context.Context, tracer trace.Tracer, name,
 ctx, span := sources.InitConnectionSpan(ctx, tracer, SourceKind, name)
 defer span.End()
 
+userAgent, err := util.UserAgentFromContext(ctx)
+if err != nil {
+return nil, err
+}
+
 // Create dsn
-query := fmt.Sprintf("database=%s&cloudsql=%s:%s:%s", dbname, project, region, instance)
+query := url.Values{}
+query.Add("app name", userAgent)
+query.Add("database", dbname)
+query.Add("cloudsql", fmt.Sprintf("%s:%s:%s", project, region, instance))
+
 url := &url.URL{
 Scheme: "sqlserver",
 User: url.UserPassword(user, pass),
 Host: ipAddress,
-RawQuery: query,
+RawQuery: query.Encode(),
 }
 
 // Get dial options
-userAgent, err := util.UserAgentFromContext(ctx)
-if err != nil {
-return nil, err
-}
 opts, err := sources.GetCloudSQLOpts(ipType, userAgent, false)
 if err != nil {
 return nil, err

internal/sources/mssql/mssql.go

@@ -22,6 +22,7 @@ import (
 
 "github.com/goccy/go-yaml"
 "github.com/googleapis/genai-toolbox/internal/sources"
+"github.com/googleapis/genai-toolbox/internal/util"
 _ "github.com/microsoft/go-mssqldb"
 "go.opentelemetry.io/otel/trace"
 )
@@ -114,8 +115,13 @@ func initMssqlConnection(
 ctx, span := sources.InitConnectionSpan(ctx, tracer, SourceKind, name)
 defer span.End()
 
+userAgent, err := util.UserAgentFromContext(ctx)
+if err != nil {
+userAgent = "genai-toolbox"
+}
 // Create dsn
 query := url.Values{}
+query.Add("app name", userAgent)
 query.Add("database", dbname)
 if encrypt != "" {
 query.Add("encrypt", encrypt)