Adding offline functionality to PWA

Proposed changes

What types of changes does this pull request introduce?

[ ] Bugfix (non-breaking change which fixes an issue)
[ ] New feature (non-breaking change which adds functionality)
[ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
[ ] Refactoring (non-breaking change that does not add functionality but makes code cleaner or more efficient)
[ ] Documentation Update
[ ] Tests (new or updated tests)
[ ] Style (changes to code styling)
[ ] CI (continuous integration changes)
[ ] Repository Maintenance
[ ] Other (please describe below)

[ ] I have read the guidelines for contributing.
[ ] The changes in this PR are as small as they can be. They represent one and only one fix or enhancement.
[ ] Linting checks pass with my changes.
[ ] Any existing unit tests pass with my changes.
[ ] Any existing end-to-end tests pass with my changes.
[ ] I have added tests that prove my fix is effective or that my feature works.
[ ] If this PR fixes an existing issue, I have added a unit or end-to-end test that will detect if this issue reoccurs.
[ ] I have added JSDoc comments as appropriate.
[ ] I have added the necessary documentation to the roar-docs repository.
[ ] I have shared this PR on the roar-pr-reviews channel (if I have access)
[ ] I have linked relevant issues (if any)