Support reflogs (#22451)

This PR adds support for reflogs on all repositories. It does this by
adding a global configuration entry.

Implements #14865

---------

Signed-off-by: Philip Peterson <philip.c.peterson@gmail.com>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

modules/setting/git.go

@@ -12,9 +12,13 @@ import (
 
 // Git settings
 var Git = struct {
-	Path                      string
-	HomePath                  string
-	DisableDiffHighlight      bool
+	Path                 string
+	HomePath             string
+	DisableDiffHighlight bool
+	Reflog               struct {
+		Enabled    bool
+		Expiration int
+	} `ini:"git.reflog"`
 	MaxGitDiffLines           int
 	MaxGitDiffLineCharacters  int
 	MaxGitDiffFiles           int
@@ -37,6 +41,13 @@ var Git = struct {
 		GC      int `ini:"GC"`
 	} `ini:"git.timeout"`
 }{
+	Reflog: struct {
+		Enabled    bool
+		Expiration int
+	}{
+		Enabled:    true,
+		Expiration: 90,
+	},
 	DisableDiffHighlight:      false,
 	MaxGitDiffLines:           1000,
 	MaxGitDiffLineCharacters:  5000,