Introduce support for configuring unlimited upload limits by allowing -1
as a valid value for anonymous and user upload MB limits.
Changes include:
- Added `envMegabytesLimitFloat` and helper functions to parse and validate limits where -1 is allowed.
- Updated validation logic to accept -1 for `AnonymousMaxUploadMB`, `AnonymousDailyUploadMB`, and `UserDailyUploadMB`.
- Added a test case to verify unlimited upload policy behavior.
Daniel Legt
f1c67c455b