Rewrite new song select footer and make it global

[frenzibyte]

• Part of Song select redesign #22204

This PR moves the new song select footer to OsuGame, adds a back button, and provides a basic set of transitions for the footer and its buttons when moving between screens.

I've also made a dummy SongSelectV2 screen to pour in all the screen-level transitions for the footer, as well as moving all V2 components to a different namespace and detaching them from the old SongSelect etc.

Preview:

CleanShot.2024-05-15.at.06.09.37.mp4

CleanShot.2024-05-15.at.06.08.59.mp4

[frenzibyte]

Added transitions for osu! logo now that #28147 was severly rejected:

CleanShot.2024-05-11.at.18.44.21.mp4

Copied mostly verbatim from SongSelect as there's not much of a difference between old and new song select at the bottom right footer to change its animation.

[peppy]

@arflyte did you ever create motion design for the footer? i feel like i recall something somewhere at some poitn

[peppy]

@frenzibyte out of curiosity is the new back button coming as part of this? it may change the animation requirements.

[arflyte]

@arflyte did you ever create motion design for the footer? i feel like i recall something somewhere at some poitn

No, it think that was the very first lazer design; the one that we used for the 2015? video.

[peppy]

I dunno, I believe at some point last year I asked for feedback on how the footer is supposed to work with multiple screens (since the icons/buttons are to change) and you 100% made something.

[bdach]

I dunno, I believe at some point last year I asked for feedback on how the footer is supposed to work with multiple screens (since the icons/buttons are to change) and you 100% made something.

Probably referring to this?

[peppy]

Probably referring to this?

That's the one. Although it doesn't really give much helpful information.

[peppy]

@arflyte re-ping since i don't think you follow conversations without ping each time

[frenzibyte]

@arflyte Also when defining animations for the footer, I need to know how the footer and animation would look like when the user opens the mod overlay, as there are side buttons like "Mod Customisation" and "Deselect All" as well as extra information components (BPM/CS/HP/OD/AR and difficulty multiplier) all placed on the footer in current versions of lazer:

[arflyte]

Hmm, I definitely need to look into the overall footer flow again. Need to double check with the other scenes and make sure the layout is consistent. Give me a day to look into this.

[peppy]

I still don't think this needs to be blocked waiting-on-design.

[frenzibyte]

I've put everything I've got for the footer so far in here. Up next, I'll look into integrating the footer with the mod overlay and open a follow-up PR for that.

For review, I recommend just checking the added/changed files on an IDE directly, as I've had to move things across and rename etc.

[frenzibyte]

This PR got extremely complex to the point I broke ShearedButton without noticing, I'll split it to a sane and easily reviewable state.