[csolution] generate fully qualified DeviceID and BoardID including vendor, even if no vendor is specified in `*.csolution.yml` file

[jkrech]

Describe the bug
When the csolution.yml file is lacking the board vendor in the boardID

  board: V2M-MPS3-SSE-300-FVP

instead of

board: ARM::V2M-MPS3-SSE-300-FVP

The expectation is that in *.cbuild.yml the vendor is always present - today the vendor is omitted!

  board: ARM::V2M-MPS3-SSE-300-FVP

This is similar to partially specified components which are fully specified in cbuild.yml

Note: This requirement is also true for *.cbuild-gen.yml generated prior to launching a generator.

To Reproduce
Take an existing CMSIS Solution project and remove the vendor from the board/device node.
Run cbuild setup and inspect the generated *.cbuild.yml file

Expected behavior
The expectation is that in *.cbuild.yml the vendor is always present

Environment (please complete the following information):

• csolution
• Version 2.7.0
• OS: windows/linux/darwin