Feature/audit certificate upload (#30223)

* feat: Add certificate upload option for audit logging settings

* Commit current changes

* Additions

* MM-62944 Fix fileupload settings not being clickable

* Support for uploading a cert for experimental audit logging cert. Pre cloud implementation in the backend

* Forgot to add new hook

* Add support for setting custom audit log certifcates in Cloud

* Permissions

* I18n

* Change order

* Linter fixes

* Linter fixes, add openapi spec

* additions for openapi

* More openapi fixes because it won't run locally

* Undo, cursor went rogue

* newline fix

* Align types properly

* Fix i18n

* Fix i18n AGAIN

* Fix error

* Update api/v4/source/audit_logging.yaml

---------

Co-authored-by: Harrison Healey <harrisonmhealey@gmail.com>
Co-authored-by: Mattermost Build <build@mattermost.com>

server/public/model/config.go

@@ -1538,6 +1538,7 @@ type ExperimentalAuditSettings struct {
 	FileCompress        *bool           `access:"experimental_features,write_restrictable,cloud_restrictable"`
 	FileMaxQueueSize    *int            `access:"experimental_features,write_restrictable,cloud_restrictable"`
 	AdvancedLoggingJSON json.RawMessage `access:"experimental_features"`
+	Certificate         *string         `access:"experimental_features"` // telemetry: none
 }
 
 func (s *ExperimentalAuditSettings) SetDefaults() {
@@ -1572,6 +1573,10 @@ func (s *ExperimentalAuditSettings) SetDefaults() {
 	if utils.IsEmptyJSON(s.AdvancedLoggingJSON) {
 		s.AdvancedLoggingJSON = []byte("{}")
 	}
+
+	if s.Certificate == nil {
+		s.Certificate = NewPointer("")
+	}
 }
 
 // GetAdvancedLoggingConfig returns the advanced logging config as a []byte.