Bump AVM1 language to 99%

[danielhjacobs]

We've talked about this for ages, it's time to finally do it.

Reasons:

• It hasn't been updated since avm1: Implement __resolve ruffle#16284
• We've just closed a long-standing issue in avm1: Extending native objects does not produce the correct object type ruffle#701
• While it wasn't a proper fix, a panic source was just resolved in avm1: Do not panic when swapping children on depth/render list desync ruffle#19594

So why not 100%:

• The last PR mentioned did not fix the fact that the depth and render list can become desynced
• There are still some known language bugs, such as Avm1Function's base_clip field should be a string path, not a display object ruffle#14562
• Not sure if it's language, but there are still known Electric Man 2 issues
• Not sure if it's language, but there is still my old issue Issue on https://www.dnai.org/d/index.html?m=1 ruffle#6254

[danielhjacobs]

@moulins approved this on Discord, @kjarosh replied with a thumbs up, and Dinnerbone suggested this a year ago. Merging in an hour unless anyone explicitly objects.