2364-draft custom legend packages

[guichoquette]

Description

I tried to create a package working exactly like the AOI panel but named legend instead. The goal was to make sure everything was working properly to then adapt the schema to what the legend package is suppose to do. I still have some issues with the package. It does not appear in app-bar and footer-bar yet as it's suppose to do.

Fixes # (2364)

Type of change

• Bug fix (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)
• This change requires a documentation update

How Has This Been Tested?

I tried to test my package in the loading packages page and the Configuration Navigator page. Strangely the Icon I chose for the package does not appear in both test I did.

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Checklist:

• I have build (rush build) and deploy (rush host) my PR
• I have connected the issues(s) to this PR
• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• My changes generate no new warnings
• I have created new issue(s) related to the outcome of this PR is needed
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

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