Make the lmms ui suitable for Qt changing (especially when setting the qt multiplier to less than 1)

### Enhancement Summary

Make the lmms ui suitable for Qt changing (especially when setting the qt multiplier to less than 1)
Be able to run lmms at 0.5 qt without the video happening
it would be nice for people who have a TINY screen, or just dont want clutter in general

(i've searched everywhere on the internet, but there was no good answer)
(this may seem like a bug, but its more of a feature as there is really nothing wrong with lmms, i just want to decrease ui size)

### Implementation Details / Mockup

running the QT_SCALE_FACTOR=0.5 Will make a quarter of the ui visible; Find a way to make the lmms logo fit as a practice

basically, the qt is set to 0.5 and the reason why it looks like this is because it cant fit within the qt value


### Please search the issue tracker for existing feature requests before submitting your own.

- [X] I have searched all existing issues and confirmed that this is not a duplicate.

No files or tests are named; first reproduce the issue with QT_SCALE_FACTOR=0.5 and trace the splash screen and main UI sizing behavior. Done means LMMS remains fully usable and its UI, including the logo and splash, is visible at the requested multiplier.

Written by the indexing model from the issue text.