[Core/Maps] Cinematic camera fixes

[jasongdove]

This achieves the same goals as https://github.com/Legends-of-Azeroth/Legends-of-Azeroth-Pandaria-5.4.8/pull/299 but does it by upgrading and fixing the existing systems (similar to TCPP/TC) instead of replacing with different systems.

• Map extractor has been updated to extract cameras in all lower case file names
  • DBC entries have Cameras folder and cameras folder; this change makes files end up in the same folder on case-sensitive filesystems
• Cinematic camera DBC loading is fixed
• Lots of viewpoint and visibility updates
• Far sight has been fixed
  • This makes creatures and objects visible during opening cinematics, etc.
  • This also partially fixes https://www.wowhead.com/wotlk/quest=12641/death-comes-from-on-high - or at least unblocks further work on that quest

[leelf00]

PR works correctly.