Description

Expands the current anchor flip logic to include all flip directions. If you notice, MudBlazor Docs does flip the anchor in the example, so the logic was already there. I added proper flip logic to each flip direction to swap anchor as needed and included it in the maxheight calculation.

Resolves #11177

How Has This Been Tested?

Visually, Viewer test PopoverFlipDirectionTest is good for this. Checked Docs as well.

Two notes that refer to flip logic entirely (not just this PR)

1. FlipMargin determines a flip, that is not the same as OverflowPadding. FlipMargin by default is set to 0, so Flipping may not occur causing a scrollbar to appear because OverflowPaddingdoes occur. If any issues arise where they believe it should flip instead of creating a scrollbar they should set flipmargin to be equal to OverflowPadding in PopoverOptions. I would suggest adding a TODO to the next major release to combine the two as it would be a breaking change. OverflowPadding is Material Design standard (equates to roughly 24px).
2. Flip-On-Open is when flip logic happens just one time and records it to the dom. If that creates a scrollbar on the popover, that scroll area will get smaller (or larger) as you scroll outside of the popover. If there's an issue the user probably wanted flip-always to have flip position recalculated every time.

Type of Changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation (fix or improvement to the website or code docs)

Checklist

• The PR is submitted to the correct branch (dev).
• My code follows the code style of this project.
• I've added relevant tests.