Windows GUI: Layout improvements

[cjee21]

Partial solution for #948

• Resize Preferences window and improve layout to ensure no tabs appear and that all languages that have long text strings are displayed fully without overflow/clipping.
• Make all modal windows spawn at the center of their parent window.
• Use VCL setting to make main form window centered instead of doing manually using code.

[cjee21]

@JeromeMartinez did what I can since I was assigned #948. I will let someone more familiar with VCL solve remaining glitches (such as #891 and I am not sure what slowdowns/defects are mentioned in #948) and do further improvements (maybe making long text lines auto-wrap etc.). This should be the last PR from me for the time being (don't think there is anything else to do on my side other than waiting for you for the Windows 11 Explorer menu) so others can work on other PRs without worrying about any potential merge conflicts.

[JeromeMartinez]

This should be the last PR from me for the time being

Thank you for you hard work.

[JeromeMartinez]

dev snapshot.