Add show interfaces breakout supported-mode CLI

[aisjoshi-cisco]

What I did

Added show interfaces breakout supported-mode [interface_name] to display supported breakout modes.

How I did it

Implemented the supported breakout-mode CLI using platform.json, added unit-test coverage for the command without ConfigDB dependency.

How to verify it

Copied the updated show module to the testbed and ran:
show interfaces breakout supported-mode Ethernet0

Verified that the output matched the platform-supported breakout modes.

Previous command output (if the output of a command-line utility has changed)

Not applicable; this is a new subcommand.

New command output (if the output of a command-line utility has changed)

show interfaces breakout supported-mode Ethernet0
+-------------+--------------------------------------------------------------------------------------------------------+
| Interface   | Supported Breakout Modes                                                                               |
+=============+========================================================================================================+
| Ethernet0   | 1x800G,1x400G,1x200G(4),1x100G(4),8x100G,4x200G,4x100G,2x400G,2x200G,2x100G,1x50G(1),1x25G(1),1x10G(1) |
+-------------+--------------------------------------------------------------------------------------------------------+ 

aisjoshi@4f038229d865:/sonic/src/sonic-utilities$ python3 -m pytest -o addopts='-vv -n 0' \
    tests/show_breakout_test.py
=========================================================================================================== test session starts ===========================================================================================================
platform linux -- Python 3.11.2, pytest-7.2.1, pluggy-1.0.0+repack -- /usr/bin/python3
cachedir: .pytest_cache
rootdir: /sonic/src/sonic-utilities/tests, configfile: pytest.ini
plugins: xdist-3.8.0, pyfakefs-6.2.0, cov-4.0.0
collected 4 items                                                                                                                                                                                                                         

tests/show_breakout_test.py::TestBreakout::test_all_intf_current_mode PASSED                                                                                                                                                        [ 25%]
tests/show_breakout_test.py::TestBreakout::test_single_intf_current_mode PASSED                                                                                                                                                     [ 50%]
tests/show_breakout_test.py::TestBreakout::test_single_intf_supported_mode PASSED                                                                                                                                                   [ 75%]
tests/show_breakout_test.py::TestBreakout::test_unknown_intf_current_mode PASSED                                                                                                                                                    [100%]

[azure-pipelines]

Azure Pipelines:
There may be pipelines that require an authorized user to comment /azp run to run.

[mssonicbld]

/azp run

[azure-pipelines]

Azure Pipelines:
Successfully started running 1 pipeline(s).

[mssonicbld]

/azp run

[azure-pipelines]

Azure Pipelines will not run the associated pipelines, because the pull request was updated after the run command was issued. Review the pull request again and issue a new run command.

[azure-pipelines]

Azure Pipelines:
There may be pipelines that require an authorized user to comment /azp run to run.

[AnoopKamath]

@prgeor , could you please help review this?

[mssonicbld]

/azp run

[azure-pipelines]

Azure Pipelines:
Successfully started running 1 pipeline(s).

[mssonicbld]

/azp run

[azure-pipelines]

Azure Pipelines:
Successfully started running 1 pipeline(s).

[mssonicbld]

Hi, there are workflow run(s) waiting for approval, you may be first-time contributor. I will notify maintainers to help approve once PR is approved. Thanks!

_{---Powered by SONiC BuildBot}

[mssonicbld]

/azp run

[azure-pipelines]

Azure Pipelines:
Successfully started running 1 pipeline(s).

[mssonicbld]

/azp run

[azure-pipelines]

Azure Pipelines:
Successfully started running 1 pipeline(s).