Clean up the use of terms for "intents" and "application requests"

I just had a look into AUTOSUITE-1480 and realised that we landed in a confusion using different terms for the new Intents in app man and for the "old" MIME-type handler.

The current Neptune documentation refers a use of the "old" MIME-type handlers, or better to say OpenDocument interface (https://doc.qt.io/QtApplicationManager/qml-qtapplicationmanager-application-applicationinterface.html#openDocument-signal) in app man as "application requests" in "Neptune 3 UI - App Requests":

https://doc-snapshots.qt.io/neptune3ui/neptune3ui-requests.html

In parallel, there is a new Intent system which is not documented yet in the appman in 5.14. The Neptune side tries to start documenting a use of it, and seem to run into a danger to create a confusion.

IMHO, it would be OK to keep using "application requests" in "Neptune 3 UI - App Requests" but only if it will clearly explain that "application requests" is a common term for the use of two features in app man:

• OpenDocument interface
• Intents

both allow initiate an action from one app in another or from an app in the System UI