Display original author and URL information when showing migrated issues/comments (#7352)

* Store original author info for migrated issues and comments

Keep original author name for displaying in Gitea interface and also
store original author user ID for potential future use in linking
accounts from old location.

* Add original_url for repo

Store the original URL for a migrated repo

Clean up migrations/tests

* fix migration

* fix golangci-lint

* make 'make revive' happy also

* Modify templates to use OriginalAuthor if set

Use the original author name in templates if it is set rather than the
user who migrated/currently owns the issues

* formatting fixes

* make generate-swagger

* Use default avatar for imported comments

* Remove no longer used IgnoreIssueAuthor option

* Add OriginalAuthorID to swagger also

modules/migrations/base/options.go

@@ -12,15 +12,15 @@ type MigrateOptions struct {
 	AuthPassword string
 	Name         string
 	Description  string
+	OriginalURL  string
 
-	Wiki              bool
-	Issues            bool
-	Milestones        bool
-	Labels            bool
-	Releases          bool
-	Comments          bool
-	PullRequests      bool
-	Private           bool
-	Mirror            bool
-	IgnoreIssueAuthor bool // if true will not add original author information before issues or comments content.
+	Wiki         bool
+	Issues       bool
+	Milestones   bool
+	Labels       bool
+	Releases     bool
+	Comments     bool
+	PullRequests bool
+	Private      bool
+	Mirror       bool
 }