Moved global PAGE_* to Profile class (#5500)

* Rewrites:
- moved PAGE_* to Friendica\Model\Profile class

* Fixed more rewrites from plain (global namespace) PAGE_* to Friendica\Models\Profile class

* CR request:
- moved all PAGE_* constants to Friendica\Model\Contact class
- fixed all references of both classes

* CR request:
- moved ACCOUNT_TYPE_* constants from boot.php to Contact::ACCOUNT_TYPE_*

* Just copy-pasted this code from boot.php, needs to be changed to `const ACCOUNT_TYPE_FOO = x;`

* Ops, melting brain cells here ... :-/

src/Network/Probe.php

@@ -398,7 +398,7 @@ class Probe
 				// This doesn't cover the case when a community isn't a community anymore
 				if (!empty($data['community']) && $data['community']) {
 					$fields['community'] = $data['community'];
-					$fields['contact-type'] = ACCOUNT_TYPE_COMMUNITY;
+					$fields['contact-type'] = Contact::ACCOUNT_TYPE_COMMUNITY;
 				}
 
 				$fieldnames = [];