feat(db): add ApplicationName to connection configuration

* Introduced ApplicationName field to identify clients in DSN
* Set default ApplicationName to "ResolveSpec"
* Updated tests for ApplicationName handling in DSN

pkg/dbmanager/providers/pgconnector.go

@@ -123,6 +123,12 @@ func buildPGXConfig(cfg ConnectionConfig) (*pgx.ConnConfig, error) {
 	}
 
 	cc.DialFunc = newDialFunc(cfg.GetConnectTimeout())
+	// Also applies to caller-supplied DSNs that do not set application_name.
+	if name := cfg.GetApplicationName(); name != "" {
+		if _, set := cc.RuntimeParams["application_name"]; !set {
+			cc.RuntimeParams["application_name"] = name
+		}
+	}
 	if cfg.GetQueryTimeout() > 0 {
 		if _, set := cc.RuntimeParams["statement_timeout"]; !set {
 			cc.RuntimeParams["statement_timeout"] = fmt.Sprintf("%d", cfg.GetQueryTimeout().Milliseconds())

pkg/dbmanager/providers/provider.go

@@ -59,6 +59,7 @@ type ConnectionConfig interface {
 	GetConnMaxLifetime() *time.Duration
 	GetConnMaxIdleTime() *time.Duration
 	GetReadPreference() string
+	GetApplicationName() string
 	GetRetryAttempts() int
 	GetRetryDelay() time.Duration
 	GetRetryMaxDelay() time.Duration