Remaining fireplaces

[BethOfDeath]

furn_t_fireplace_01:

• Added collision mesh, reducing calculations from 298 tris to 108 (and split so the interior parts which can only be collided with by projectiles are separate)
• Deleted 15 hidden faces. Rotated some edges for better shape around opening to interior.
• Data Transferred UV layout from MelchiorDahrk's higher-poly Telvanni Fireplace Replacer model (with permission, per https://discord.com/channels/210394599246659585/566703593336340483/1478884802865270784) Very slight remaining distortion on backside, but I'm not sure that's ever visible in-game.
• Weighted normals.
• Vanilla: 9373 bytes; new: 10328 (+10%)

furn_fireplace10

• Simplified and split collision mesh from 82 tris to 74.
• UV rework to fix some stretch and seams. There's only so much I could do for where the fireplace sides meet the large "floor" part, but I was able to improve things a bit.
• Added vertices to mantle for better vertex lighting
• Normals work
• Added LOD to drop drawcall of extremely thin trim texture. I'd just remove that entirely, were it my decision.
• Vanilla: 28090 bytes; new: 37074 (+32%)

in_imp_fireplace_grand

• Simplified collision mesh where possible, adjusted to better fit visual mesh where needed, split the heck out of the chimney.
• Reassigned faces on left interior side of fireplace to the tx_imp_fireplace_03 texture, as per other similar parts of the model.
• Merged UVs and scooted them over a bit to fix dark line in center of mantle front, where the UVs fold back over themselves to mirror the texture.
• Added a couple extra edges to flaring part of chimney to correct remaining texture distortion which ensued after I combined the UV islands and adjusted for as much distortion as I could without them.
• Combined firebrick base UV islands. Slightly increased scale of resulting island to better match texel density of firebrick back wall. This also helped with hiding seams on front corner bevels.
• Mirrored one side of detail texture tx_imp_fireplace_02 to correct the baked-in lighting as much as possible and match _01 texture's mirroring and apparent light source direction.
• Various other UV work to make model make more physical sense.
• Added edge loops and verts to top of mantle to enable better vertex lighting, such as from lights placed on it.
• Removed extremely thin row of triangles which was hidden by another mesh from the bottom of the tx_imp_fireplace_03(?) textured mesh side pillars.
• Vanilla: 20527 bytes; new: 19633. (-4%)

Fixes rest of #81