Support for skinning/customising the UI

[TonyWildish-BH]

We'd like to add an NHS logo to the UI for our SDE, maybe skin the site to fit our branding, add custom links to documentation relating to our environment, make some local customisations etc. This comes down to two things:

1. Skinning. How can we change the appearance of the site without having to patch our fixes into the UI code whenever we update from upstream?
2. Customisation. What's the current development procedure for enhancing or customising the UI? I've seen the documentation, but it's not clear from that if there's any support for debugging the React code without building a full deployment, which is a) slow, and b) hard to debug because the code is minified. Is there anything to make debugging easier and faster?

Many of our tweaks will be site-specific, not something that should be contributed back to the upstream codebase. It would be great if that could be supported by a clean separation of 'core' and 'custom' UI features.

[West-P]

Following as we would also like to offer this customisation when using Azure TRE.

[jonnyry]

Also us :-)

[marrobi]

We have uses of the TRE who have built their own UI. This points to the TRE backed API. They develop and deploy their UI independently to whatever compute they need. They choose not to deploy the UI as part of the TRE deployment (is a setting in config).

If there are specific requirements for the UI in this repository to allow basic skinning, customisation, then please create issues with specific requirements, even screenshots/mockups, and hopefully someone time to pick it up, or it might be copilot is our friend :)

On debugging, the UI can be debugged locally, but needs an API (can also be run locally). This is the same as any react app. See: https://code.visualstudio.com/docs/nodejs/reactjs-tutorial#_debugging-react

[jonnyry]

Related: #2851

[marrobi]

@jonnyry well found, maybe split #2851 into three separate "tasks", and close this one?