Move cutscenes skips out of Patches.py, improve documentation, add a new one and improve on two existing ones

[GSKirox]

An attempt to start on #2213

This PR moves all cutscenes skips done in Patches.py to a new file Cutscenes.py, and tries to document them by interfacing some of the hacks done with clearer functions, or by adding comments on their purpose. Most of them have been cleaned of unnecessary byte changes, which are a ton easier to detect nowadays with decomp.
The hacks have been sorted by "Vanilla walkthrough" order.

There's also a couple of additions :

New cutscene shortened :

• Master Sword cutscene in Temple of Time has been shortened to 20 frames from 230 and 210 respectively for child => adult and adult => child.

Already existing cutscenes skips shortened further

• Lake Hylia water restored after killing Morpha, shortened to 2 frames from 199.
• Bottom of the Well draining after playing Song of Storms in the windmill, shortened to 3 frames from 180.

These two cutscenes waited for their respective flags to be set before being cut. With the new functions we can easily set the flag on the first frame and then immediately stop.

Aside from that, the behaviour to all cutscenes should be strictly identical to before and if not then i made a mistake somewhere !
They were all left untouched because the purpose of this change was not so much to improve on existing skips rather than making them easier to either improve or toggling them off in future devs.