Allow list of rotation conditions in file rotation logic

[CollinHeist]

This implements the behavior described in #1174 , and allows for specification of a list (or tuple/set) of conditions for file rotation, like so:

from loguru import logger

logger.configure(
  handlers=[
    dict(
      sink='file.log',
      rotation=['12h', '10 MB'],
    )
  ]
)

[Delgan]

Thanks for your PR @CollinHeist. Apologies for the delay.

Admittedly, I was initially rather reluctant to add such a feature, for the sake of simplicity. Though, I agree that this is not actually very cumbersome to add, and indeed, and it can visibly be useful to several users.

Just to let you know that I haven't forgotten the PR and plan to merge it after releasing a new debug release. Thank you again for your work.

[Delgan]

Merged, thanks for your patience!