Improve Azure Pipelines template hygiene

There is a wide variety of quality in the Azure pipelines templates hosted in this repo. We should go through all of the templates and:

- Convert any implicitly typed template parameters to [type-safe parameters](https://learn.microsoft.com/en-us/azure/devops/pipelines/process/runtime-parameters?view=azure-devops).
- Ensure parameter defaults are only set in one place (for parameters that are passed through multiple template levels).
- Document any parameters or variables which aren't commented/documented somewhere at least once.
- Put quotes around strings wherever possible
- This is to prevent unexpected conversions to numbers, dates, etc. These are well documented issues with yaml.