Rebrand to INBUXA: product name, protocol greetings, sign-in page, calendar templates, logos, README

One branding module (types::brand!) supplies the name to every protocol
greeting, the HTTP realm, the startup banner, Received headers, the
user agent, the IMAP ID response and calendar PRODIDs. The sign-in and
calendar pages take ihasmail's palette and font and the INBUXA logo, and
calendar emails embed the INBUXA lockup. Default calendar and address book
names follow. Protocol identifiers (urn:stalwart:jmap, vnd.stalwart Sieve
extensions) and upstream copyright notices are unchanged.

tests/src/jmap/contacts/addressbook.rs

@@ -36,7 +36,7 @@ pub async fn test(test: &TestServer) {
     assert_eq!(
         list[0],
         json!({
-            "name": "Stalwart Address Book ([email protected])",
+            "name": "INBUXA Address Book ([email protected])",
             "description": (),
             "sortOrder": 0,
             "isSubscribed": true,
@@ -146,7 +146,7 @@ pub async fn test(test: &TestServer) {
                 "id": addressbook_id,
             }),
             json!({
-                "name": "Stalwart Address Book ([email protected])",
+                "name": "INBUXA Address Book ([email protected])",
                 "description": (),
                 "sortOrder": 0,
                 "isSubscribed": true,