Adds support for surrounding text in visual/visual-line/visual-block
mode by re-using the `AddSurrounds` operator. There is no default
binding though so the user must follow the instructions to enable it.

Note that the behaviour varies slightly for the visual-line and
visual-block modes. In visual-line mode the surrounds are placed on
separate lines (the vim-surround extension also indents the contents but
I opted not to as that behaviour is less important with the use of code
formatters). In visual-block mode each of the selected regions is
surrounded and the cursor returns to the beginning of the selection
after the action is complete.

Release Notes:

- Added action to surround text in visual mode (no default binding).

Fixes #13122