Add bear wave emote

I've updated the emotes.json and emotes.png to have bear waving emote

I requested this change at https://github.com/codecat/tm-better-chat/issues/12#issuecomment-2557672133

Sorry about the messy PR. Haven't done a lot of these.

I have tested & confirmed that it works on my machine.

In case BetterChat does not integrate my suggestions, for anyone who wants to replace meow emote with bear emote, see https://github.com/ReedyBear/tm-better-chat/tree/replace-meow-with-bear ... this will only change it on your screen. 🐻

The PR itself looks good, but this makes it easy to accidentally type bear and have the emote shown. I don't believe this emote is very popular either (I've never seen it used before). I don't know if it makes sense to add this to the global list tbh.

Perhaps "bearhello" or "hibear" or "bearwave" would be better? I like hibear.

I totally respect that, I haven't seen people use it either. I will, however, present some points in favor of adding bear wave:

• Bears are cute
• There is only one other furry gif emote
• There is a lot of spare space left on the emotes board, and no emotes have been added this year.
• It could be given a name like BearTest to signify that it might be removed in a later patch
• Maybe people would use it if it were available? Maybe? I would use it! lol
• 

Again, I totally respect if you choose not to add it! I had to make my case though :D

And big thanks for making BetterChat. Also, v glad kitty meow is available :)