feat: add command for setting window size to a specific value

[maxle5]

Objective:

The resize command currently supports increasing/decreasing a window by a a certain value, however it does not currently support setting a window height/width to a specific value (e.g. set width to 25%, or set height to 500px)

Solution:

• Created a new SetWindowSize command
  • This calculates the delta/offset required to achieve the desired size, then invokes the resize command
• Refactored resizeAmount parsing logic to to a new service ResizeParsingService, this is used to parse the resize amount (i.e. translate "+3%" to 0.03)
• Updated readme to include set width/height command

[lars-berger]

Thank you for this 👍 The code looks squeaky clean

However, one concern is we'd essentially have 2 distinct commands disguised as one. IMO it'd be better to just move this stuff to its own command eg. set height 400px

[maxle5]

@lars-berger, Ok I can do that! Do we have any concerns with set <height | width > 400px being similar to the existing set <floating | tiling | minimized | maximized> command?

[lars-berger]

@maxle5 I reckon it's fine - there's bound to be commands that have the same verb (eg. we currently have resize <height | width> ... and resize borders ...)

[maxle5]

@lars-berger, should be ready to be reviewed again, let me know if there is anything else you'd like me to change!