Older version of Git don't support unix timestamp dates

Adds new reveal commit in Repositories view code lens command option
Adds new show commits in Search Commits view code lens command option

Removes ` to Clipboard` from menu commands
Removes Show Commit Details from view context menus
Removes Show File History from view context menus

Fixes issue stash reveal button
Updates reveal|open in view icons
Adds gating to reveal methods

Makes git flags type safe

Cleans up navigation key support for git commands
Changes search git command to show a quick pick menu of commit commands
Adds navigation key support to search git commands to reveal commits
Removes incorrect multiselect of repos in search git command
Adds navigation key support to stash git commands to reveal stashes
Changes stash list git command picker to stay in context
Changes Show In View to be Open in Search Commits View
Changes Show In View to be Open in File History View
Adds Reveal in Repositories View command in commit quick picks
Changes commit quick pick commands (ordering, descriptions, etc)
Adds progress notification to revealCommit & reveal parent walking
Changes findNode to use a loop & canTraverse callback & adds cancelation
Changes findCommit to search for commit in all branches

Adds left arrow to go back if there is no text value