Add local dev deployment for LTI 1.3

[martinclaus]

This adds a docker compose deployment and instructions and configuration to set up the TAO LTI 1.3 devKit as the LTI platform to initiate the login flow.

The goal is to improve testing of the LTI 1.3 Authenticator both locally and via CI.

[martinclaus]

It seems that the LTI 1.3 library on which the devkit is build isn't correctly implementing the LTI 1.3 specifications, or more precisely, the OICD Connect specifications. Issues (oat-sa/lib-lti1p3-core#154, oat-sa/lib-lti1p3-core#160) are opened.

[danielmcquillen]

I noticed that a c.LTI13Authenticator.jwks_endpoint configuration setting is used in the docs but this PR has a c.LTI13Authenticator.endpoint setting ... are those both valid?

[martinclaus]

I noticed that a c.LTI13Authenticator.jwks_endpoint configuration setting is used in the docs but this PR has a c.LTI13Authenticator.endpoint setting ... are those both valid?

@danielmcquillen This PR is quite outdated and stalled. The c.LTI13Authenticator.endpoint setting does not exist in more recent releases anymore. The correct one to use is c.LTI13Authenticator.jwks_endpoint.