sonic-mgmt: fix t0-isolated-d128u128s2 topo

[ccroy-arista]

Description of PR

This PR contains the following changes, in order to achieve a functional t0-isolated-d128u128s2 topo:

• The field 'bp_interfaces' in the t0-isolated-d128u128s2 yml file is corrected to 'bp_interface' i.e. w/o the 's'.
• Added more VMs, to support the larger number of VMs needed for the topo.
• Added the missing leaf template file for the topo.
• Fixed the synthesis of the MACs used in ansible roles so that it does not error out after 256 interfaces.

Additionally, this PR fixed the 'bp_interfaces' for t0-isolated-d128u128s1 yml file.

Summary:
Fixes # (issue)

Type of change

• Bug fix
• Testbed and Framework(new/improvement)
• Test case(new/improvement)

Back port request

• 202012
• 202205
• 202305
• 202311
• 202405

Approach

What is the motivation for this PR?

To achieve a functional t0-isolated-d128u128s2 for use in sonic-mgmt tests.

How did you do it?

Made a series of fixes/updates as detailed in the summary above.

How did you verify/test it?

Confirmed that the testbed server can now be successfully configured as a result of these changes, and subsequently ran the sonic-mgmt test suite.

[mssonicbld]

The pre-commit check detected issues in the files touched by this pull request.
The pre-commit check is a mandatory check, please fix detected issues.

Detailed pre-commit check results:
trim trailing whitespace.................................................Passed
fix end of files.........................................................Failed
- hook id: end-of-file-fixer
- exit code: 1
- files were modified by this hook

Fixing ansible/roles/eos/templates/t0-isolated-d128u128s2-leaf.j2

check yaml...............................................................Passed
check for added large files..............................................Passed
check python ast.....................................(no files to check)Skipped
flake8...............................................(no files to check)Skipped
flake8...............................................(no files to check)Skipped
check conditional mark sort..............................................Passed

To run the pre-commit checks locally, you can follow below steps:

1. Ensure that default python is python3. In sonic-mgmt docker container, default python is python2. You can run
   the check by activating the python3 virtual environment in sonic-mgmt docker container or outside of sonic-mgmt
   docker container.
2. Ensure that the pre-commit package is installed:

sudo pip install pre-commit

3. Go to repository root folder
4. Install the pre-commit hooks:

pre-commit install

5. Use pre-commit to check staged file:

pre-commit

6. Alternatively, you can check committed files using:

pre-commit run --from-ref <commit_id> --to-ref <commit_id>

[sdszhang]

@r12f for viz.

[r12f]

a few issues is already fixed by this PR: https://github.com/sonic-net/sonic-mgmt/pull/15454/files.

this PR is missing the template, because the topo is generated. it will be better to get the generator fixed too.

[r12f]

@ccroy-arista , this PR is merged now: #15454.

you might need to merge with the master branch, and I believe certain issues will be gone.

[mssonicbld]

@ccroy-arista PR conflicts with 202405 branch

[ccroy-arista]

A recent merge from a different PR contained a fix that is also present in this PR, hence the conflict with 202405.

I will open up a separate PR for 202405 branch.

[ccroy-arista]

PR for manual cherry-pick to 202405 posted: #15786