providers: Add canchat.org, decent.im, projectsegfau.lt, suchat.org, trung.fun, xmpp.earth

Closes #67 (closed), #72 (closed), #74 (closed), #93 (closed), #95 (closed), #109 (closed)

This was needed to replace !370 (merged) because of a fatal problem with the provider manager that was fixed by !383 (merged).