Improve Tile Select Functionality with Modifiers & Shortcuts

[Pseudorandom-Pseudonym]

Is your feature request related to a problem? Please describe.
Selecting tiles can be a bit slow.

Describe the solution you'd like
Implement the use of modifiers like ctrl/shift/alt to alter how the mouse is used to select tiles. e.g. hold shift and drag to select an area, ctrl and hold to select in a continuous line. Add alt to begin a new selection i.e the old selction is unselected on the next click.

Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.

Additional context
Just getting this one on the books. I haven't figured out all the details.