SAK-50557 LTI exceptions thrown for some tools placed in users workspace

[hornersa]

Jira: https://sakaiproject.atlassian.net/browse/SAK-50557

Refer to the screencast attached to the jira for details about the proposed fix.

Also, the proposed CSS change helps better align the tool title of a deployed external tool with the other tool titles in a given site's tool menu. (Currently the icon elements with class fa are two pixels too wide compared to icons with class si.)