Add Replace in... to context menus

Add "Replace in..." to project tree and working set context menus.

https://trello.com/c/3cKG28Fn/1309-replace-in-from-file-tree

cc @njx 

It might look better like:
```
CommandManager.register(Strings.CMD_FIND_IN_FILES,       Commands.CMD_FIND_IN_FILES,       _showFindBar);
CommandManager.register(Strings.CMD_FIND_IN_SELECTED,    Commands.CMD_FIND_IN_SELECTED,    _showFindBarForSubtree);
CommandManager.register(Strings.CMD_FIND_IN_SUBTREE,     Commands.CMD_FIND_IN_SUBTREE,     _showFindBarForSubtree);

CommandManager.register(Strings.CMD_REPLACE_IN_FILES,    Commands.CMD_REPLACE_IN_FILES,    _showReplaceBar);
CommandManager.register(Strings.CMD_REPLACE_IN_SELECTED, Commands.CMD_REPLACE_IN_SELECTED, _showReplaceBarForSubtree);
CommandManager.register(Strings.CMD_REPLACE_IN_SUBTREE,  Commands.CMD_REPLACE_IN_SUBTREE,  _showReplaceBarForSubtree);
```