Update membranes for visual variety

[HexapodPhilosopher]

Brief Description of What This PR Does

Makes different membrane types more visually distinct.

Tweaks membrane UV generation to pull the texture closer to center, making the texture on the model look closer to the way it looks in the texture image (less stretched in the center).

Adjusts membrane shader to vary fresnel effect (and thus visibility in the center of the mesh) by membrane type wigglyness. Adjusts visibility of 2nd normal map (for wiggling effect) in the same way.

Replaces standard and damaged textures for all membranes.

Still to do:

• Make carbonate texture more solid-looking (also requiring new normal.
• Possibly fix texture rotation (it's rotated 135 degrees currently).

Related Issues

Progress Checklist

Note: before starting this checklist the PR should be marked as non-draft.

• PR author has checked that this PR works as intended and doesn't
  break existing features:
  https://wiki.revolutionarygamesstudio.com/wiki/Testing_Checklist
  (this is important as to not waste the time of Thrive team
  members reviewing this PR). This includes gameplay testing by the PR author.
• Initial code review passed (this and further items should not be checked by the PR author)
• Functionality is confirmed working by another person (see above checklist link)
• Final code review is passed and code conforms to the
  styleguide.

Before merging all CI jobs should finish on this PR without errors, if
there are automatically detected style issues they should be fixed by
the PR author. Merging must follow our
styleguide.