fix(frontend): update mui Tree* dependency for FieldsView.tsx

[jeffycyang]

Description

I've been using opendiffy/diffy and building from source with some customization. Upon doing so I've noticed the default frontend @mui/lab Tree* components have been deprecated and now must be imported from @mui/x-tree-view with TreeView having been renamed to SimpleTreeView as well as some slight changes in component props to both SimpleTreeView and TreeItem.

Changes

Adds @mui/x-tree-view as frontend dependency and replace TreeView & TreeItem to be imported from aforementioned package with migrated syntax following the following docs:

• https://mui.com/blog/lab-tree-view-to-mui-x/
• https://mui.com/x/migration/migration-tree-view-v6/

Bug Reproduction & Testing Change

One can verify the bug by standing up the docker-compose stack, building the diffy image from source locally by replacing L53 in docker-compose.yml with something like:

    image: local_diffy:latest
    build:
      context: .
      dockerfile: Dockerfile 

On master:

1. stand up docker compose stack locally building diffy from source following the above modification to the compose file, ex. docker compose -p diffy-local -f docker-compose.yml up --build

2. make a request to the diffy server at 8880 (request failure doesn't matter for this bug reproduction), ex.

    curl -v -X --url="http://localhost:8880"
   

3. navigate to the frontend at http://localhost:8888

4. clicking on the entry on the left hand Endpoints list will show nothing under right side Fields and there will be a warning in the developer console about the deprecation, see screenshot:

Do the same on this branch (building diffy image from source) and it will work as it did before, screenshot for reference:

Additional Context & Consideration

The current diff/diffy:latest image, does not have this problem likely due to a frontend docker build cache with a @mui/lab version prior to the deprecation.

It might be worth considering adding a frontend dependency lock file so this issue does not arise for future users who choose to build from source.