Make the query window wider

[msm-code]

Your checklist for this pull request

• I've read the contributing guideline.
• I've tested my changes by building and running mquery, and testing changed functionality (if applicable)
• I've added automated tests for my change (if applicable, optional)
• I've updated documentation to reflect my change (if applicable)

What is the current behaviour?
The query window is a bit narrow, and cuts of larger yara rules.

What is the new behaviour?
Some changes here:

1. During the initial edition, editor takes a whole width of the window - it's basically free real estate:
   

2. Later this is reduced to a half window's width - still more than 5/12 and is enough for a bit wider rules:
   

Test plan
Take a look at the screens. (or run mquery and ensure that the app really looks like this and there are no weird issues).

Closing issues

fixes #195

[msm-code]