[PR] Adding dynamic menu

[LuchoTurtle]

closes #4

This PR adds a menu that is dynamic, meaning it uses the information stemming from a json object to render the contents.
The json object consists of MenuItems (with an id, title and tiles - a list of MenuItems below).

[LuchoTurtle]

I've managed to get the contents of json object to be rendered on the side menu drawer. Looking to Future-proof this and check how reorder could be implemented.

[nelsonic]

In principal we will use the same position-based ordering for the drawer menu
so if you can get the drag-and-drop re-ordering working in Flutter-land that's awesome! 🤞

[LuchoTurtle]

Reordering should now work locally. Meaning it is not saving the changes to the json file. Reordering only works on the items on the same level, though.

Screen.Recording.2023-04-28.at.20.04.30.mov

[LuchoTurtle]

I've managed to increase the code coverage to near 98%. Will tackle on getting it to 100%.

I've successfully tested dragging and dropping. Flutter's longPress doesn't work, so I had to create a custom function using startGesture to simulate drag an drop on widget tests.

[LuchoTurtle]

Fixed a few bugs regarding reordering and fixed the decoration border that was overlapping on nested elements. Added both of these to the README.
Also fixed the CI to use the latest version of Flutter. By using collection, flutter_test was having conflicts with the collection package, so I had to force it to use the latest.

Not yet marking this for review because I want to add a simple navigation to a page displaying the menu item information. After that, everything should be thoroughly documented and ready for submission.

[LuchoTurtle]

This should be done for review. Added navigation, tests to cover the full app and added a CI to fix typos on a separate PR. Because the changes added are substantial, there's a chance I got a typo here and there.

[nelsonic]

@LuchoTurtle could you please record a short video/GIF of the final result. 🎥
@SimonLab if you have time please do an initial pass at reviewing this. 🙏

[LuchoTurtle]

Screen.Recording.2023-05-12.at.09.57.19.mov

Here's an overview:

• working i18n.
• navigation on static menu items.
• navigation on dynamic menu items.
• showing support for icon, emoji and images that are formatted to 64x64px.
• customization of dynamic menu text colour.
• persistable reordering of dynamic menu items.

[LuchoTurtle]

Could this PR be merged? I believe it's complete and easily mergeable 🆗

[nelsonic]

Yeah, I reviewed it at the time. 👀
Had asked @SimonLab to have a look, but I think he's focussed on other priority items. 👌
Merging. ✅