Add the Bubble Flower power-up

[Copilot]

Adds the Bubble Flower and the Bubble entity it shoots, as described in #111.

In Bubble form the player shoots bubbles that drift forward, catch what they run into, and can be bounced
on. Shooting one opens a 1.2 second window that fits two bubbles, counting the one that opened it; once
the window runs out both come back at once, and the next shot opens a fresh one.

Bubble entity

• Travels forward with air friction and drifts upwards as its horizontal speed drops.
• Cube hitbox, billboard sprite, one of four looks picked at random on spawn.
• Rebounds off blocks with a squish animation, and never passes through them. Rebounds notify the block,
  so target blocks and the like react.
• Holds a single entity as a regular passenger, so vanilla handles syncing and saving it. The bubble
  resizes to a slightly larger cube around whatever it holds; the drawn size eases into place while the
  hitbox changes in one step.
• A trapped entity has its AI disabled, tumbles as if thrown in space, and is released unharmed when the
  bubble goes. The tumble leans along the bubble's heading at the moment of capture.
• Catching a Super Mario entity swallows it: it spins, shrinks away, and is replaced by loot rolled from
  super_mario:gameplay/bubble_capture — a coin by default, and a real collectible entity rather than a
  stored stack, so it keeps a coin's size and spin.
• No health, like a painting: any real hit pops it. Wind charges deal no damage, so they only blow it
  around. Explosions and portals work because the bubble runs the usual "inside block" effects.
• Can be stomped for a vertical boost that keeps the stomper's horizontal momentum. The owner cannot stomp
  their own bubble for a short grace period, otherwise shooting one while airborne is a free flight.
• Pops on its own after 5 seconds, or 5 seconds after catching something.

What can be trapped

Entities under 2 blocks in both directions with a base max health of 20 or less, or anything in
super_mario:bubble_can_trap. Health is read from the base attribute, so a leader zombie still counts as
an ordinary zombie. super_mario:bubble_cannot_trap holds the exceptions — bosses, and players.

Empty bubbles steer slightly towards a nearby trappable entity, as an aim assist rather than as homing.

Core module

The power-up charge system needed work to support firing in bursts:

• New BURST_RECHARGE charge counting: the first use opens a window of a set length, the uses that follow
  run out the same window, and every charge comes back at once when it is over. The Bubble Flower runs on
  2 charges per 24 tick window.
• New TIMED_RECHARGE charge counting, one charge back at a fixed interval, built on the previously
  unused cooldown field. Both countdowns are now started from inside the properties, so an action never
  has to drive the cooldown itself.
• How a power-up counts its charges moved into a PowerUpCharges record (counting, max, interval), so it
  is configured from data instead of being guessed from whichever fields the action happens to set:
  shoot_projectile takes a single charges field, and any counting can be paired with any max and
  interval.
• Power-up properties are only synced when the charge count actually changes, instead of on every tick of
  a running cooldown.
• addEntity() split into useCharge() and trackEntity(), so the tracked entity list no longer grows
  forever outside FROM_ACTIVE_ENTITIES.
• Projectiles are shot centered on the eye line instead of resting their bottom on it.

Notes

• All the new content lives in the super_mario module; the charge system changes are in mubble-core.
• The bubble is customisable from NBT: lifetime, filled_lifetime, texture, capture_motion, and
  vanilla Passengers for what it holds.
• Run ./gradlew runDatagen after checking out: the generated sounds.json still lists the rebound sound
  that this branch removes.

Closes #111

[Hugman76]

The cooldown timers and refill conditions need to be checked up against Mario Wonder again, I'm not sure about them.

[Hugman76]

After trying in wonder, firing a bubble opens a window of roughly 1,2 seconds where you can fire at most 2 bubbles (counting the initial bubble). Then that window rests until the next time you fire a bubble.
We might need a new refill type for this, and make it highly configurable

[Hugman76]

I believe we don't HAVE to put the tag in the datagen to make it available for other datapacks

[Hugman76]

Unnecessary comment

[Hugman76]

This tag should be renamed as bubble/catch_as_collectible. Comment is unnecessary.

[Hugman76]

There are too many comments here. No need to clear them all, but some constants are very easy to understand without any comment.

[Hugman76]

This is a weird comment

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. It should be replaced with capitalized Intellij region/endregion

[Hugman76]

Unnessecary comment.