Remove storing of unused attributes

[agbpatro]

Description

This PR removes storing of rawBytes for few reasons:-

• Datastore sends Payload and not RawBytes from the vehicle.
• Our metrics for datastore were instrumented against length rawRawBytes when in reality we send Payload to them
  -streamMessage.ToBytes() was doing unnecessary flatbuffer to bytes transformation which the server doesn't really need
• Removing unused helper methods around RawBytes like Encode, ensureEncoded

Type of change

Please select all options that apply to this change:

• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Bug fix (non-breaking change which fixes an issue)
• Documentation update

Checklist:

Confirm you have completed the following steps:

• My code follows the style of this project.
• I have performed a self-review of my code.
• I have made corresponding updates to the documentation.
• I have added/updated unit tests to cover my changes.
• I have added/updated integration tests to cover my changes.

[agbpatro]

closing for now. Fixing only metrics issue in #154