Spacepackets

Changed

- `CcsdsTimeProvider`: Add `len_packed`, mark `len` as deprecated
- `ecss.pus_1_verification`:
- `Service1Tm`: `time_provider` needs to be passed explicitely now, no default value.

Fixes

- `ecss.tm.PusTelemetry`: Various fixes for new optional timestamp feature, added checks
that timestamp is not None. `time_provider` does not have a default value anymore and needs
to be passed explicitely.
- `CdsShortTimestamp`: The new `from_now` (and former `from_current_time`) classmehod now creates
the timestamp from a UTC datetime.
- `CdsShortTimestamp`: The `datetime.datetime` instance returned from `as_date_time` now
returns has the `datetime.timezone.utc` set as the time zone information.

Added

- `CdsShortTimestamp`:
- Add new `from_now` classmethod and deprecate `from_current_time`.
- Add `__eq__` implementation which only compares CCSDS days and ms of day.

Added

- `CdsShortTimestamp`
- Add `__add__` magic method impl which allows adding timedeltas
(but only timedeltas)
- Add new constructor `from_date_time` to create timestamp from `datetime.datetime`
- Add `ms_of_day` and `ccsds_days` properties
- (breaking): `ms_of_day` staticmethod renamed to `ms_of_today`

Changed

- `CcsdsTimeProvider`: Renamed `as_datetime` to `as_date_time`. Old function still there but marked
deprecated.
- (breaking): The `CcsdsTimeProvider` is now optional for the ECSS TM packet constructors, but
needs to be supplied explicitely. There is no automatic construction of a specific version of the
CDS timestamp with 16 bit days anymore if no time provider is passed. If this behaviour
is still required, `CdsShortTimestamp.empty()` can be passed explicitely. If not time provider
is passed, it is assumed the time field is empty.
- (breaking): `PusServices` renamed to `PusService`, not a flag enum.
- (breaking): `Service17Tm.unpack`: Time reader needs to be passed explicitely as second argument.
- (breaking): Rename `pus_1_verification.Subservices` to `pus_1_verification.Subservice`
- (breaking): Rename `pus_3_hk.Subservices` to `pus_3_hk.Subservice`
- (breaking): Rename `pus_5_event.Subservices` to `pus_5_event.Subservice`
- (breaking): Rename `pus_17_test.Subservices` to `pus_17_test.Subservice`

- Improved Time Handling inside for the TM module, make it possible
to use different timestamps
- Introduces `CcsdsTimeProvider` abstraction to allow this.
- Improve implementation of `CdsShortTimestamp` class
- Basic `AbstractPusTm` class
- Basic `AbstractSpacePacket` class
- Singular enum names for CFPD module

- Refactored and improved TLV API and handling. Implementation is also a bit more efficient
- Basic CFDP version support: Sanity checks on version field. Only version 2 supported

- Improved documentation, first docstrings
- Added more re-exports, for example for the `ccsds` module
- Added several dunder method implementations, especially `__repr__`, `__str__` and `__eq__`
- Improved CFDP packet stack API, several improvements derived from the implementation
of a CFDP handler using it
- Added generic abstraction for CFDP File Data and File Directive PDUs in form of the
`AbstractPduBase` and `AbstractFileDirectiveBase`
- Generic `UnsignedByteField` implementation. This is a data structure which is regularly
used for something like variable sized identifier fields. It provides a lot of boilerplate
code like common dunder implementations
- Split up and improve test structure a bit

- Update `pyproject.toml` file for full support, but still keep `setup.cfg` for now
- API improvements for PUS Verificator
- Setter properties for sequence count and APID in ECSS module
- Make `as_u32` function of `RequestId` public