feat(platform): provide method to get a specific application

[danielwiehl]

This commit adds the ManifestService.getApplication method to get a specific application. If not found, by default, throws an error unless setting the orElseNull option.

PR Checklist

Please check if your PR fulfills the following requirements:

• [x] The commit message follows our guidelines
• [x] Tests for the changes have been added
• [ ] Docs have been added or updated

PR Type

What kind of change does this PR introduce?

• [ ] Fix
• [x] Feature
• [ ] Documentation
• [ ] Refactoring (changes that neither fixes a bug nor adds a feature)
• [ ] Performance (changes that improve performance)
• [ ] Test (adding missing tests, refactoring tests; no production code change)
• [ ] Chore (other changes like formatting, updating the license, removal of deprecations, etc)
• [ ] Deps (changes related to updating dependencies)
• [ ] CI (changes to our CI configuration files and scripts)
• [ ] Revert (revert of a previous commit)
• [ ] Release (publish a new release)
• [ ] Other... Please describe:

Issue

Issue Number: #

Does this PR introduce a breaking change?

• [ ] Yes
• [ ] No

Other information