Limit MATLAB Test product installation check to decision, condition, and mcdc metric levels

[mw-kapilg]

Summary

• The MATLAB Test product installation check in CodeCoverageSummaryPluginService is now only performed for decision, condition, and mcdc metric levels.
• For statement and function metric levels, coverage summary generation no longer requires the MATLAB Test product to be installed.
• The license('test', 'matlab_test') check continues to apply for all metric levels.

[davidbuzinski]

Definite improvement. There's still a puzzle to me because we default to mcdc so this won't be on by default in most cases, even if the user provides all of the other required information.

Also, there's still the problem that if the user requests a coverage report with any other format, this won't show up. It seems like in almost all real use-cases where the user provides enough info to collect coverage, this won't show up.

[mw-kapilg]

Definite improvement. There's still a puzzle to me because we default to mcdc so this won't be on by default in most cases, even if the user provides all of the other required information.

Also, there's still the problem that if the user requests a coverage report with any other format, this won't show up. It seems like in almost all real use-cases where the user provides enough info to collect coverage, this won't show up.

For the first issue:
We can change the action's default to an empty string. On the MATLAB side, an empty value means "auto-detect" — if MATLAB Test is installed, use mcdc; otherwise, fall back to statement. If the user explicitly sets a level that requires MATLAB Test (decision/condition/mcdc) and it's not installed, we respect their choice and skip coverage generation entirely.

For the second issue, we don't have a better architecture to support it at the moment

[mw-kapilg]

Closing this PR and will create a new one with proposed changes