lara: fix jump-twist interruptions

[lahm86]

Resolves #932.

Checklist

• I have read the coding conventions
• I have added a changelog entry about what my pull request accomplishes, or it is an internal change

Description

The gravity check added as part of #890 was failing in some cases because there is a 4 frame window at the start of the jumping animation where gravity is zero, so if roll was pressed here the jump would be cancelled.

The changes here now reflect tomb3 (aside from the additional twist inputs, but that will be covered separately against #931).

@aredfan has done some additional animation testing with me on this build as follows to be thorough:

• The original T-pose softlock issue from lara: fix jump-twist state softlock #890 under low ceilings
• Running jump + action to grab a ledge
• Running jump into a swan dive
• Running jump off a ledge to enter fast fall
• Backward jump off a ledge to enter fast fall
• Normal backward jump into standing still state
• Backward jump off a higher ledge, but not high enough to kill Lara