[css-anchor-position] Rename position-try-options to position-try-fallbacks

[fantasai]

We changed position-try-options to always put the base styles first, so it's really fallbacks -- and we talk about it being a list of fallbacks -- so I think we should actually name it by what we call it.

[css-meeting-bot]

The CSS Working Group just discussed [css-anchor-position] Rename `position-try-options` to `position-try-fallbacks` , and agreed to the following:

• RESOLVED: rename position-try-options to position-try-fallbacks

The full IRC log of that discussion

<chrishtr> fantasai: when we were designing position-try longhands, the reordering option reordered all of the options
<chrishtr> fantasai: now it's really just fallbacks that are there - just the base style and the current trys
<chrishtr> fantasai: suggesting we could rename to fallback to reflect this
<miriam> +1 it's clearer
<emilio> +1
<una> q+
<lwarlow> +1 from me
<Rossen7> ack una
<bkardell_> +1 (I was a 👍 on the issue already)
<chrishtr> una: wanted to say that I don't necessarily have strong opinions on this, but Tab did. Move to next meeting?
<chrishtr> rossen: Seeing strong consensus on this, can always re-open. Other concerns from anyone?
<chrishtr> RESOLVED: rename position-try-options to position-try-fallbacks