[WIP] [MM-55031] OAuth Outgoing Connection App integration (#25379)

* OAuthOutgoingConnection model

* added store

* make generated

* add missing license headers

* fix receiver name

* i18n

* i18n sorting

* update migrations from master

* make migrations-extract

* update retrylayer tests

* replaced sql query with id pagination

* fixed flaky tests

* missing columns

* missing columns on save/update

* typo

* improved tests

* remove enum from mysql colum

* add password credentials to store

* license changes

* OAuthOutgoingConnectionInterface

* Oauth -> OAuth

* make generated

* merge migrations

* renamed migrations

* model change suggestions

* refactor test functionsn

* migration typo

* refactor store table names

* updated sanitize test

* cleanup merge

* refactor symbol

* list endpoint

* oauthoutgoingconnection -> outgoingoauthconnection

* signature change

* i18n update

* granttype typo

* naming

* api list

* uppercase typo

* i18n

* missing license header

* fixed path in comments

* updated openapi definitions

* sanitize connections

* make generated

* test license and no feature flag

* removed t.fatal

* updated testhelper calls

* yaml schema fixes

* switched interface name

* suggested translation

* missing i18n translation

* address comments

* updated i18n

server/channels/api4/api.go

@@ -143,6 +143,9 @@ type Routes struct {
 	Reports *mux.Router // 'api/v4/reports'
 
 	Limits *mux.Router // 'api/v4/limits'
+
+	OutgoingOAuthConnections *mux.Router // 'api/v4/oauth/outgoing_connections'
+	OutgoingOAuthConnection  *mux.Router // 'api/v4/oauth/outgoing_connections/{outgoing_oauth_connection_id:[A-Za-z0-9]+}'
 }
 
 type API struct {
@@ -273,6 +276,9 @@ func Init(srv *app.Server) (*API, error) {
 
 	api.BaseRoutes.Limits = api.BaseRoutes.APIRoot.PathPrefix("/limits").Subrouter()
 
+	api.BaseRoutes.OutgoingOAuthConnections = api.BaseRoutes.APIRoot.PathPrefix("/oauth/outgoing_connections").Subrouter()
+	api.BaseRoutes.OutgoingOAuthConnection = api.BaseRoutes.APIRoot.PathPrefix("/oauth/outgoing_connections/{outgoing_oauth_connection_id:[A-Za-z0-9]+}").Subrouter()
+
 	api.InitUser()
 	api.InitBot()
 	api.InitTeam()
@@ -319,6 +325,7 @@ func Init(srv *app.Server) (*API, error) {
 	api.InitIPFiltering()
 	api.InitReports()
 	api.InitLimits()
+	api.InitOutgoingOAuthConnection()
 
 	srv.Router.Handle("/api/v4/{anything:.*}", http.HandlerFunc(api.Handle404))