fix: main window fullscreen state when closing and re-opening

[alexbarnsley]

Summary

Checklist

• Documentation (if necessary)
• Tests (if necessary)
• Ready to be merged

[codecov]

Codecov Report

Merging #1760 into develop will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff            @@
##           develop    #1760   +/-   ##
========================================
  Coverage    60.45%   60.45%           
========================================
  Files          362      362           
  Lines         9040     9040           
  Branches      1824     1824           
========================================
  Hits          5465     5465           
  Misses        3399     3399           
  Partials       176      176

---

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 d588552...7d0b40f. Read the comment docs.