refactor: migrate protected branch fields into one json column and support system users (#39735)

1. migrate protected branch fields into one json column
2. use the dropdown list for push/force-push user selection, and Actions
user can be added into the list now.

services/forms/repo_form.go

@@ -156,11 +156,9 @@ type ProtectBranchForm struct {
 	EnablePush                    string
 	WhitelistUsers                string
 	WhitelistTeams                string
-	WhitelistDeployKeys           bool
 	EnableForcePush               string
 	ForcePushAllowlistUsers       string
 	ForcePushAllowlistTeams       string
-	ForcePushAllowlistDeployKeys  bool
 	EnableMergeWhitelist          bool
 	MergeWhitelistUsers           string
 	MergeWhitelistTeams           string