HaikuDepot: Url -> Identifier

This change will rename the confusing "url" within
HaikuDepot to be "identifier" in line with
corresponding changes in pkg kit and HDS.  Also at
the same time support is introduced for HDS
repos' meta-data to artificially match against
multiple repos; as requested for the future R1B3
release process.  Some tidy-ups and extensions have
been made to the JSON schema-to-model and the
schema-to-parser scripts.

Change-Id: I402e7d610986039f58d72028bda7de977e9115e2
Reviewed-on: https://review.haiku-os.org/c/haiku/+/2986
Reviewed-by: Adrien Destugues <[email protected]>

docs/user/app/KeyStore.dox

@@ -171,7 +171,7 @@
 		the key that you are looking for.
 	\param[in] secondaryIdentifierOptional Use this query parameter to indicate
 		if the secondary identifier has to match. When set to \a false, a
-		result will be returned, even if the \a secondaryIdentifer does not
+		result will be returned, even if the \a secondaryIdentifier does not
 		match.
 	\param[out] key A BKey object to copy the found data to. Any existing data
 		in the key will be overwritten in case there is a match.

docs/user/app/_app_keystore.dox

@@ -207,7 +207,7 @@
 	why in the \ref BApplication::ReadyToRun() hook we check for the
 	availability of the key. If it is not available, or it does not work, the
 	user will be redirected to the authentication tool. The key will be stored
-	as a password. It will be identified by the identifer "CoolWebService".
+	as a password. It will be identified by the identifier "CoolWebService".
 
 	\code{.cpp}
 	void