Changes:
- [x] Cursor at the start during yank operations on objects (`yip`,
`yab` etc).
- [x] Refactors this: Trim all leading and trailing whitespace from
inner multiline bracket selection.
  - This leaves a nicely indented line when doing `ci{` `vi{d` etc
  - [x] Checks for empty selection
  - [x] Removed moving cursor to the start in visual bracket operations

This cleans up the previous implementation by providing a simpler check
in `surrounding_markers`, instead of calling a new function in
`expand_object`. No functionality was changed there except for handling
the empty selection and removing some cursor adjustments that should not
have been there after further testing.

Release Notes:

- N/A