Unifi-video

Added
* `UnifiVideoAPI.get_recordings()` for smarter recording listing
* `UnifiVideoAPI.{active,managed}_cameras` collections
* `UnifiVideoAPI.get_camera()`: new kw arg: `managed_only`
* `UnifiVideoCamera` attributes: `state`, `managed`, `provisioned`,
`managed_by_others`, `disconnect_reason`, `connected`, `last_recording_id`,
`last_recording_start_time`, `last_seen`, `last_seen_ndt`
* Datetime utilities
* Keyword arg for `UnifiVideoAPI` init: `utc_offset_sec`
* Throw `UnifiVideoHTTPError` on HTTP 400 from UniFi Video
* `UnifiVideoRecording` attributes: `start_time_utc`, `end_time_utc`
* `UnifiVideoAPI.delete_all_recordings()`

Changed
* Accept start and end times as `datetime`, `int` or `str` in
`UnifiVideoCamera.recording_between()`
* UTC offset is now per UniFi Video instance instead of per camera
* Use `UnifiVideoAPI.get_recordings()` internally
* Refactored `UnifiVideoCamera.refresh_cameras()` to account for
all three camera collections (`UnifiVideoAPI.{,managed_,active_}cameras`)
* `UnifiVideoCamera.recording_between()` uses new dt util for the
`{start,end}_time` args

Added
* `UnifiVideoRecording.motion()` to download recording's motion image

Changed
* Supported versions range (to cover UniFi Video v3.10.13)
* Documentation changes

Fixed
* Names in the deployment script

Added
* Included *UVC G4 Bulle*t and *UVC G4 Pro* in the list of supported camera
models

Changed
* Expanded the supported versions range to include the latest UniFi Video,
[v3.10.11][ufv31011].

Fixed
* Guard against `get()` on potential NoneType (occurred while instantiating
`UnifiVideoCamera` against unmanaged camera)

Fixed
* Bug in camera model check

Added
* `UnifiVideoCamera.get_recording_settings()` (8)

Changed
* Renamed underscored names `_version` and `_name` in `UnifiVideoAPI` to
signal it is OK to rely on them in application code (9)