Changes to layer properties can't be undone, aren't treated as changes to the file

[quinnyo]

Pixelorama version: v1.1.1-stable

Where did you download Pixelorama from?
GitHub Releases

Issue description:
Various changes can be made to layers that aren't undoable and don't get counted as changes to the file.
"Various changes" includes changing a layer's name, visibility, opacity, lock, etc. and the values in Layer Properties other than blend mode.

Not being able to undo a changed name or opacity is a nuisance (particularly when it undoes something elsewhere, which can be hard to notice) but I think the more significant result of this is that the file isn't marked as dirty/changed, so the file can be closed without being prompted that there are unsaved changes.

Steps to reproduce:

• Open a new file
  • (or any file that has no unsaved changes)
• Rename Layer 1 to PLayer won or something that amuses you
• Note that the (*) doesn't get appended to the tab/title bar.
• Note that the file/app can be closed without prompting (and if the file exists, the new layer name is not preserved)