Small changes to prescribedLinearTranslation module

[leahkiner]

Describe your use case
There are a few changes that should be made to the existing prescribedLinearTranslation module to match the current changes being applied to the prescribedRotation1DOF module. These changes include:

1. Updating release notes to point out the renamed module variable coastOptionBangDuration and the associated setter and getter methods.
2. Add const keyword to the module setter function parameters
3. Fixing up comments

Describe alternatives solutions you've considered
N/A

Additional context
N/A