Panel spacing review. e.g. Image whitespace and spacing regression

[anthony-chaudhary]

After adding split panes for compound file it has introduced some new assumptions around spacing. We need to:

• [ ] Refactor out "full screen" vs split screen assumptions. e.g. in canvas_scale_global()

• [ ] Gain better clarity on spacing around the named components, e.g. toolbar, sidebar, annotation area, and specific panes. For example if sidebar is larger, then annotation area becomes smaller etc. This already happens but is baked a little too much into specific components vs being clearly part of that new paradigm.

• [ ] In full screen mode, for images, vertical resizing does not always work as expected with new split panels. e.g. it introduces unwanted extra spaces

• [ ] Sometimes split panes seems to introduce an extra scrollbar

• [ ] Sometimes extra white space is added while this can't be annotated, it can be confusing that sometimes the background is white and sometimes the split panels default grey.

• [ ] Need Regression clarity here. e.g. that someone doesn't come and think they are "fixing" it by removing padding and having it align, while it makes it harder for person to annotate etc. Maybe we can just have a doc somewhere that says like "we expect 3px border, we expect xyz" etc.

Context that in some cases we can have overlap, e.g. so it looks like a padding issue, but then it's actually "cutting" off key annotation space, so need clarity on where we edit this.

For now just adding slightly more space in canvas_scale_global() sizing for images, but opening this since we have many other media types this could affect and generally needs to be stronger.

This is not a huge priority as mostly edge cases

Alignment example

e.g. settings this to align-start if media core is open (instead of centering) Centering makes sense if it's closed

white space example