TCP Server timeout / ignore transaction id

- New property to disable the transaction id check (not recommended but requested)

- Optimized an issue with non-responding Modbus TCP servers.

Versioning on CI fixed

Enhancing data type conversions and serial client

- Extensions to convert from/to naive data types have a parameter to `inverseRegisters` order. (by @Luke092) (Closing Issue #15 more precisely)

- Better async behaviour for serial client.

- Updated to C# 9.0
- Updated packages

Enable byte flip (endianness) from/to string

Added a switch to flip bytes from network order. Needed for string conversion (from/to) to handle little and big endians.

Fixing NullReference Exception

- Removed null-reference exception
- Added Extensions to convert values to `ModbusObject`s

Fixed disconnect issue

- Removed a potential dead-lock scenario when disconnecting while on reconnect.

- Modbus clients have a optional `CancellationToken` on `Connect()` and `Disconnect()`.

Hotfix TCP client

Fixed (1 change)

- The Modbus TCP client on unix systems creates an `IOException` on connection loss - catch that exception instead of the `EndOfStreamException`.

Fixed (3 changes)

- The Modbus TCP client will now recognize (again) a connection close from the remote and start the reconnect cycle
- The Modbus TCP server recognizes the connection close from the client as well and terminate the running tasks.
- The Modbus TCP server catches the rising `NotImplementedException`s and will not crash anymore on invalid requests.

Added (5 changes)

- Added this changelog.
- Added a `ModbusObject` as base class for `Coil`s, `DiscreteInput`s and `Register`s. The property `Type` of `ModbusObjectType` will tell you the actual meaning.
  For naming reasons the old classes are still present and used.
- `*.snupkg` (Debug Symbols) for the NuGet packages are available on my Gitlab.
- New package `AMWD.Modbus.Proxy`
  - *TCP to TCP* can be used when a remote device only accepts one connection but multiple clients want to request the information (or as Gateway [on a NAT device]).
  - *TCP to Serial* can be used to bring a Modbus RTU (RS485) device into your local network.
- Added a custom console logger to the console demo application.

Changed (5 changes)

- The `Value` property of all structure classes is replaced by `RegisterValue` for 16-bit values ([Holding | Input] `Register`) and `BoolValue` for 1-bit values (`Coil`, `DiscreteInput`).
- All servers and clients can use an `ILogger` implementation for detailed logging in the instances.
- Using more `TimeSpan` for timeouts instead of integer values with different meanings (seconds, milliseconds?!?).
- Updated Gitlab CI procedure for automatic deployment to NuGet.org.
- Code cleanup and C# 8.0

Removed (1 change)

- git attributes not needed and therefore deleted.
- `FakeSynchronizationContext` was never used.

Declaring v0.9.0