Make greentea tools standalone

[rwalton-arm]

We'd like to make the greentea tools standalone again, rather than part of the mbed-os-tools mono repo.

• Bring mbed_host_tests (htrun) into standlone greentea python library Bring mbed_host_tests (htrun) into standlone greentea python library #302 @rajkan01
• Separate Greentea host tools (python) into their own repo @wernerlewis Standalone Greentea host #301
• Update the Readme of standalone greentea htrun @rajkan01 Update the htrun readme #307 307
• Fix flake8 errors for htrun #310
• Set up Greentea host tools PR testing (GitHub Actions) #309
• Decide on where to place mbed specific host tests #312
• Remove the unused/dead from standalone greentea htrun @LDong-Arm (won't do, see explanation below)
• Remove tools/host_tests from mbed-os @LDong-Arm (won't do, see below)
• Remove unimplemented gt command line arguments @wernerlewis (PR Standalone Greentea host #301 in review )
• Check use and un-used the htrun command line arguments @rajkan01
• Remove un-implemented htrun command line arguments python source from standalone greentea htrun repo @rajkan01
• Verify fastmodel support works in standalone greentea htrun @rajkan01 ( Unable to verify, see explanation below))
• Remove mbed reference from https://github.com/ARMmbed/greentea/ #314
• See if we can delete or "blank" the host-tests that are inside the mbed-os repo- figure out what is depending on the host-tests inside mbed-os #315 @rajkan01 Remove host_tests from mbed-os/tools mbed-os#14932
• Make mbedgt use mbed-tools detect --json for device detection, to avoid needing to depend on any Python library for device detection #317
• Make a new pypi package greentea-host for holding host-test stuff #318
• Remove mbedgt/gt from ARMmbed/greentea #319 @rajkan01 Remove gt and cleanup #321
• Update mbed-fastmodel-agent so it works with iris.debug #323
• Document how to generate test results and interpret results (check, format?) #311
• Set up Greentea host tools continuous deployment pypi releases (GitHub Actions) #313
• Refactor Mbed host-tests to use standalone greentea python lib @rajkan01 Refactor mbed libraries host_tests to use standalone greentea htrun mbed-os#14755 (It is blocked until mbed-greentea PyPI gets released)
• Update Mbed OS CI (e.g. pip install -U greentea-host, ...) #316

[LDong-Arm]

Explanation for scripts in host_tests:
Some of the scripts are not directly referenced by the code base, but actually greentea-client can instruct htrun to run the script with specified name:

GREENTEA_SETUP(20, "default_auto");

in this case htrun looks for default_auto.py in its "search paths".

host_tests in htrun:
The host_tests from htrun itself is in the "search path", but users can also add additional directories using the -e/--enum-host-tests option. We intend to keep those scripts in htrun, so tests have a choice to use them without supplying their own host scripts.

host_tests in mbed-os:
The host scripts bundled in tools/host_tests/ in mbed-os are legacy, but removing them without breaking Mbed CLI 1 is not straightforward. For example, they are referenced by tools/tests_api.py which is coupled with Mbed CLI 1's mbed test command. When we stop supporting Mbed CLI 1 in the future, we can remove host_tests and command line support altogether from the Mbed OS tree.

[rajkan01]

Verify fastmodel support works in standalone greentea htrun:

mbed-fastmodel-agent is an interface python module to ARM fast model and this fastmodel agent is invoked by htrun to run host tests with fast models. Unfortunately mbed-fastmodel-agent is using pyCADI (based Python 2.7) which is part of the ARM fast model and it got deprecated in the latest version and replaced by Iris CADI which leads to significant changes in the mbed-fastmodel-agent to work so I could not able to completely verify the flow of fast model inside htrun and only checked ran the following command to make sure it invokes the fast model agent APIs

[Patater]

All tasks closed. Mission complete.