x11: fixes for dpi scaling

[fwsmit]

This may solve issue with incorrect window sizes.
It also fixes mouse position calculations. So the correct notification will be closed again when clicking on it.

Fixes: #950 #966

[codecov-commenter]

Codecov Report

Merging #965 (87865ed) into master (7aa5adc) will decrease coverage by 0.01%.
The diff coverage is 0.00%.

@@            Coverage Diff             @@
##           master     #965      +/-   ##
==========================================
- Coverage   60.34%   60.32%   -0.02%     
==========================================
  Files          42       42              
  Lines        6415     6417       +2     
==========================================
  Hits         3871     3871              
- Misses       2544     2546       +2     

Flag	Coverage Δ
unittests	60.32% <0.00%> (-0.02%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
src/draw.c	0.97% <0.00%> (ø)
src/x11/x.c	0.00% <0.00%> (ø)

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 7aa5adc...87865ed. Read the comment docs.

[vpont]

Is it enough to fix the text dimensions? I mean, there are other elements that depend on the scale, like icon dimensions, alignments, etc which also use round()

[fwsmit]

Is it enough to fix the text dimensions? I mean, there are other elements that depend on the scale, like icon dimensions, alignments, etc which also use round()

Probably not, but I don't want to risk breaking notifications with random ceils.