Clone Input when the workflow execution forks

[tovask]

Proposed changes

Closes #5598

When the execution forks into multiple branches during a workflow, the subsequent subtemplates under a Matcher Name based condition check run with a new clone of the Input, so that they won't overwrite each other's extracted shared variables.

(This is not an issue when there are simle conditional subtemplates without a Matcher Name, because in that case the execution won't fork due to the slightly different logic. Though I'm not sure if this is intentional.)

Checklist

• Pull request is created against the dev branch
• All checks passed (lint, unit/integration/regression tests etc.) with my changes
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)

[GeorginaReeder]

Thanks so much for your contribution @tovask ! :)

[Mzack9999]

lgtm - The shared context was initially intentional as nested templates would have been able to share values and modify them (for example a nested login), but I agree that it's just cleaner to consider each branch independent and pass values copies.