* Improve content presentation and add multiple content display support

This commit:
* Improves LTI content presentation handling, and correctly displays LTI DL content in the LMS
* Adds support for presenting multiple DL content items on the same block

* Addressing review comments

* Nits

* Improve test and fix issue

[BD-24][TNL-8072]

* Improve logging and error message presentation

* Add full deep linking content data on studio

* Internationalize LTI 1.3 templates

* Add translation tooling

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

* Update translations

* Address review comments

* Additional logging improvements

* Address review comments, fix test

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

* Implement ltiResourceLink content presentation

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

* Add tests

* Fix serializer required fields issue

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

* Update version and changelog

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>

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

This change moves the LTI configuration retrieval to
a Django model that will LTI configuration.
The current model proxies back the to blocks to keep
backwards compatibility.

See reasoning for change at:
https://github.com/edx/xblock-lti-consumer/blob/master/docs/decisions/0001-lti-extensions-plugin.rst