Move middleware context handler logic to service (#29605)

* middleware: Move context handler to own service

Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>

Co-authored-by: Emil Tullsted <sakjur@users.noreply.github.com>
Co-authored-by: Will Browne <wbrowne@users.noreply.github.com>

pkg/services/ldap/settings.go

@@ -94,8 +94,12 @@ var config *Config
 
 // GetConfig returns the LDAP config if LDAP is enabled otherwise it returns nil. It returns either cached value of
 // the config or it reads it and caches it first.
-func GetConfig() (*Config, error) {
-	if !IsEnabled() {
+func GetConfig(cfg *setting.Cfg) (*Config, error) {
+	if cfg != nil {
+		if !cfg.LDAPEnabled {
+			return nil, nil
+		}
+	} else if !IsEnabled() {
 		return nil, nil
 	}