Refactor `git.Command.Run*`, introduce `RunWithContextString` and `RunWithContextBytes` (#19266)

This follows 
* https://github.com/go-gitea/gitea/issues/18553

Introduce `RunWithContextString` and `RunWithContextBytes` to help the refactoring. Add related unit tests. They keep the same behavior to save stderr into err.Error() as `RunInXxx` before.

Remove `RunInDirTimeoutPipeline` `RunInDirTimeoutFullPipeline` `RunInDirTimeout` `RunInDirTimeoutEnv`  `RunInDirPipeline`  `RunInDirFullPipeline`  `RunTimeout`, `RunInDirTimeoutEnvPipeline`, `RunInDirTimeoutEnvFullPipeline`, `RunInDirTimeoutEnvFullPipelineFunc`.

Then remaining `RunInDir` `RunInDirBytes` `RunInDirWithEnv` can be easily refactored in next PR with a simple search & replace:
* before: `stdout, err := RunInDir(path)`
* next: `stdout, _, err := RunWithContextString(&git.RunContext{Dir:path})`

Other changes:
1. When `timeout <= 0`, use default. Because `timeout==0` is meaningless and could cause bugs. And now many functions becomes more simple, eg: `GitGcRepos` 9 lines to 1 line. `Fsck` 6 lines to 1 line.
2. Only set defaultCommandExecutionTimeout when the option `setting.Git.Timeout.Default > 0`

1 files changed, 4 insertions, 7 deletions

diff --git a/modules/git/git.go b/modules/git/git.go
index 14940d1f16..6b7dbfd169 100644
--- a/modules/git/git.go
+++ b/modules/git/git.go
@@ -124,7 +124,9 @@ func VersionInfo() string {
 func Init(ctx context.Context) error {
 	DefaultContext = ctx
 
-	defaultCommandExecutionTimeout = time.Duration(setting.Git.Timeout.Default) * time.Second
+	if setting.Git.Timeout.Default > 0 {
+		defaultCommandExecutionTimeout = time.Duration(setting.Git.Timeout.Default) * time.Second
+	}
 
 	if err := SetExecutablePath(setting.Git.Path); err != nil {
 		return err
@@ -295,10 +297,5 @@ func checkAndRemoveConfig(key, value string) error {
 
 // Fsck verifies the connectivity and validity of the objects in the database
 func Fsck(ctx context.Context, repoPath string, timeout time.Duration, args ...string) error {
-	// Make sure timeout makes sense.
-	if timeout <= 0 {
-		timeout = -1
-	}
-	_, err := NewCommand(ctx, "fsck").AddArguments(args...).RunInDirTimeout(timeout, repoPath)
-	return err
+	return NewCommand(ctx, "fsck").AddArguments(args...).RunWithContext(&RunContext{Timeout: timeout, Dir: repoPath})
 }