Create screen for general plugin setting

[mdp97]

Create a screen for general plugin setting which are accessible through the "manage apps" section in the Jira settings (Admin view)

User story

1. As a Mira system administrator
2. I want to customize the app
3. So that it fits the needs of my company's users.

Acceptance criteria

• Visible screen with all the button in the jira settings
• ...

Definition of done

• Can be demoed
• Fully tested with the unit test
• Code well structured and formatted (hold to code conventions)
• Clear explaination of code
• No syntax/runtime errors
• Codes are peerly reviewed
• Communicate issues by leaving comments on github

[emiliakaf]

These general settings should be accessible through the Administration (the gear button top right) -Manage Apps. You can see the suggested position and and example of administration of a plugin in the screenshot. You can already create placeholders for the sections planned (see mockup https://docs.google.com/document/d/1kryYVnLDnkynQrUmu13G6sUjypJvnNzcW-GSgJ5Gg1w/edit) Suggested name: Agile Planning Platform. Another ideas are welcome :)

[emiliakaf]

Additional acceptance criteria:

• [ ] When clicking on Administration - Manage apps a system administrator finds the Agile Planing Platform section