Issues with Granitos

[MrGaming-18113]

SuperTux version: SuperTux v0.6.3-1075-gd9eb29f9c (Latest one)
I have multiple bug reports with the new NPC added on the game "Granitos" and I decided to achieve them all here instead of making multiple issues.

Bug 1: When stepping above a huge granito while Tux gathered the Egg powerup (Or any other powerup) the Tux sprite will immediately glitch between falling frames. (Sorry if recorded at 30 FPS)
Bug 2: When default granitos spawn on slopes and try to walk, they will stuck on the slopes until those interact with Tux.
Bug 3: When a little grantio sits on a big granito and Tux try to step on the little one, somehow Tux will forcely be moved to the direction where the granito sitted.

https://github.com/SuperTux/supertux/assets/74196506/c1746fd2-afeb-4e03-99e0-c97ea4759edc
(First one)

https://github.com/SuperTux/supertux/assets/74196506/45bbec34-24e7-4223-96d8-f072f834659f
(Second one)

https://github.com/SuperTux/supertux/assets/74196506/726cf1ae-2c06-4664-8051-116095d42ccf
(Third one)

[MatusGuy]

I believe the first one is known and caused due to some weird collision shenanigans. The others are new tho. Thx for the report

[Rusty-Box]

I can add some more:

• Standing in front of a Granito and then ducking/crawling - Tux will not get up when releasing the DOWN key
• Rock Rolling freaks out when in front of a Granito. It's like Tux gets force pushed out of its hitbox.