Add test for image

Fix broken tests

Add `html` content type serializer

Fix broken tests

Add serializer for `link` content type

This implements the endpoint that LTI tools use to return the deep linking configuration to the LMS, along with the `ltiResourceLink` type to allow testing with demo tool.

Signed-off-by: Giovanni Cimolin da Silva <giovannicimolin@gmail.com>

Signed-off-by: Giovanni Cimolin da Silva <giovannicimolin@gmail.com>

Remove the OIDC view from XBlock and return OIDC url directly.

* Move LTI 1.3 Key management to model

This:
- Removes the need to load the modulestore on every public keyset endpoint call.
- Simplifies the block structure and parent method overrides.
- Removes private key, client id and related parameters from XBlock fields

It also includes a migration from the data stored in the block to the model.

* Cleanup unused test helpers

* Version bump

* Addressing review comments

Because the courseware microfrontend loads units inside iframes,
the LTI modal ends up being squished and generally ugly.
This PR introduces a new message sent to the parent window to request
a modal containing the contents of the LTI launch iframe.

https://openedx.atlassian.net/browse/TNL-7410

Also fixes a few untreated exceptions and remove unused variables.

Signed-off-by: Giovanni Cimolin da Silva <giovannicimolin@gmail.com>

This commit adds support for the LTI 1.3 Access token endpoint, as detailed in the IMS Security Framework.
The token is generated using the consumer's private key (stored in the XBlock) after validating the message sent by the LTI Tool using it's public key.

Signed-off-by: Giovanni Cimolin da Silva <giovannicimolin@gmail.com>

Features:
Implement LTI 1.3 launch support.
Add LTI 1.3 passthrough views as LMS plugins.

Toggle aria-hidden attribute on modal window open/close; Set title attribute on iframe to display name of component; Remove aria-labelledby attribute from modal body; Make modal overlay id attribute unique'