MM-63200: unrestricted local admin (#30295)

* use SessionHasPermissionToCheckRestrictedAdmin

* allow unrestricted config edits from localmode

* check model.PermissionManageSystem for getLatestVersion

* simplify/clarify RequestTrialLicense semantics

* rename for clarity

* whitespace from linter

---------

Co-authored-by: Mattermost Build <build@mattermost.com>

server/public/model/config.go

@@ -3677,7 +3677,8 @@ const ConfigAccessTagAnySysConsoleRead = "*_read"
 // The 'access' tag '*_read' checks for any Sysconsole read permission and grants access if any read permission is allowed.
 //
 // By default config values can be written with PermissionManageSystem, but if ExperimentalSettings.RestrictSystemAdmin is true
-// and the access tag contains the value 'write_restrictable', then even PermissionManageSystem, does not grant write access.
+// and the access tag contains the value 'write_restrictable', then even PermissionManageSystem, does not grant write access
+// unless the request is made using local mode.
 //
 // PermissionManageSystem always grants read access.
 //