docs(examples): add authN/authZ for supply chain app example

[petermetz]

Description

We want to be reasonably sure that we haven't forgotten anything basic from the JWT support code in the API server and the best way to find out is to try and make one of the end to end examples work with JWT authorization so that we can put ourselves in the shoves of someone who is developing an application with the framework leveraging the plugins and the API server.
While doing the above, likely some issues will come to light that otherwise would've been hidden until we go to 1.0.0 and people start using it so this way we can get ahead of that.
If any issues arise, please make sure to create new, separate tasks for fixing those that can also be addressed by separate PRs so that we avoid one huge PR that updates the examples and also updates core/API-server/core-api package code at the same time.
By the end of it in the PR resolving this issue we should only have the changes that are touching only the examples folder code because everything else necessary (prerequisites) was done already.

Acceptance Criteria

1. The supply chain example is locked down by default with authorization, e.g. JWT validation is enabled
2. To keep it user friendly the example tutorials need to end with valid JWTs printed to the command line at the very end so that end users can see/use them with the least amount of hassle possible
3. Do not mix changes between examples and core code (further explained above but wanted to underline it here too)
4. Make sure the documentation is updated accordingly as well
5. Publish the container image to GHCR and also make sure to update the root README.md and the inner supply-chain-app README.md with those images. This part will be done in issue docs(examples): update container image for supply chain #1815

[elenaizaguirre]

@petermetz In point 5 of Acceptance Criteria you say "Publish the container image to GHCR" but I cannot do it before merge changes because I need the npm version, so I think the right order is this:

1. Create the PR for these changes
2. Publish new npm packages (I don´t have permissions)
3. Create and publish the container image (I have permissions for this)
4. Create another PR to update README with newest container image

[petermetz]

@petermetz In point 5 of Acceptance Criteria you say "Publish the container image to GHCR" but I cannot do it before merge changes because I need the npm version, so I think the right order is this:

1. Create the PR for these changes
2. Publish new npm packages (I don´t have permissions)
3. Create and publish the container image (I have permissions for this)
4. Create another PR to update README with newest container image

@elenaizaguirre Oops, you are right. We can break this issue down into two separate ones to model the reality of the dependent steps. Could you create that other issue and move the container image publishing criteria over to that one from this one?