Dropdown menu alignment fixes

This does a couple things in an attempt to resolve, at least temporarily, our dropdown menu alignment issues.

1. Removes the &[style] { ... } override @MartijnCuppens added. This alone resolves #32484 (closed), but this caused other issues with the menu alignment classes on static dropdowns.

2. So, to fix that, now the menu alignment classes .dropdown-menu-start and .dropdown-menu-end are positioned via Popper and use the --bs-position CSS variable. I've removed the left and right properties for those.

3. And, in combination, I've scoped those left and right properties to instances of the -start and -end classes that are used with data-bs-display="static". It's not the best, but it resolves the alignment near as I can tell for all dropdown menus, static or otherwise.

In the docs, I've added a temporary set of all the dropdown alignment options at the top of the page so I can quickly check things. I'll migrate this to the cheatsheet pages I think before merging, but didn't want to do that until getting some eyes on this.

Whatcha think—good enough for solving our woes ahead of Beta 2?

/cc @ffoodd @XhmikosR

TODO:

• clean up squash any patches manually
• needs tests