Fix project manager display at small window sizes (3.x)

[Calinou]

3.x version of #61211.

• Don't use minimum size for project order/filter controls. This also allows the filter field to become longer at large window sizes.
• Hide the loading label instead of changing its opacity. This causes a reflow during loading, but this is preferable to having the UI overflow.
• Hide the About button on Android as it will spawn a dialog that's too large to be closed on most screens.
• Hide the language dropdown on Android as it doesn't work correctly.

This allows the project manager to be displayed correctly at much lower window sizes than previously.

This partially addresses #60728. Further changes need to be made to the editor itself to reduce cases of UI elements overlapping (including preventing access to the About dialog within the editor).

[akien-mga]

#61215 is not trivial to cherry-pick due to some changes in the UI code for the project manager. Since it's related to this PR, maybe you can include it here as a first cherry-pick commit and then your further changes, so the whole can be tested together?

[Calinou]

#61215 is not trivial to cherry-pick due to some changes in the UI code for the project manager. Since it's related to this PR, maybe you can include it here as a first cherry-pick commit and then your further changes, so the whole can be tested together?

Done:

@aaronfranke I noticed that the number of asset library columns is not set when switching tabs for the first time. The number of columns is only set when the window is resized. This means that if you resize your window to a very small size then switch to the Asset Library tab, you will still see 2 columns instead of 1. This occurs on both master and 3.x.

[akien-mga]

Thanks!