Improve LTI documentation and configuration
Documentation at https://documentation.opencast.org/develop/admin/modules/ltimodule/ needs some reviewing, as it lacks information about setting prop.lti.player.url, or states to uncomment <sec:custom-filter after="BASIC_AUTH_FILTER" ref="oauthProtectedResourceFilter" />" although it doesn't exists.
It could be useful to review basic configuration files which doesn't seem to have defined defaults for these neither.
There are no "prop.lti.*" properties in the 3.x code base. These may have been used in UCT LTI code from 1.6.x, but are no longer used.
For the series LTI tool, the player is hard-coded to theodul in modules/matterhorn-lti/src/main/resources/tools/series/xsl/episodes.xsl:
<xsl:attribute name="href">/engage/theodul/ui/core.html?id=<xsl:value-of select="mp:mediapackage/@id" /></xsl:attribute>