Refactor: removal of GlobalC::UOT

[jinzx10]

Reminder

• Have you linked an issue with this pull request?
• Have you added adequate unit tests and/or case tests for your pull request?
• Have you noticed possible changes of behavior below or in the linked issue?
• Have you explained the changes of codes in core modules of ESolver, HSolver, ElecState, Hamilt, Operator or Psi? (ignore if not applicable)

Linked Issue

#4079

What's changed?

The global variable "GlobalC::UOT" (an object of class ORB_gen_tables) is removed from the code. Instead, ESolver_KS_LCAO becomes the owner of the only object of class ORB_gen_tables.

Any changes of core modules? (ignore if not applicable)

Various functions & classes relying on GlobalC::UOT now have "const ORB_gen_tables*" as an explicit argument.