Improve search experience

This PR improves the overall search experience inside minus which includes more keybindings, bug fixes and APi improvements. These are planned:-

[x] Moving left and right with left and right arrow keys
[x] Jumping to beginning and end of text using Home and End keys respectively.
[x] Jumping from one word to another C+left and C+right key combinations.
[x] Support for adding/deleting characters from any position.
[x] Add tests related to keybindings in search mode.

AMythicDev / minus