tests: clean up tests

- Move all module tests to their own directories.

- Avoid duplication of `// import`.

tests/modules/programs/mbsync/mbsync-expected.conf

@@ -0,0 +1,55 @@
+# Generated by Home Manager.
+
+IMAPAccount hm-account
+CertificateFile /etc/ssl/certs/ca-certificates.crt
+Host imap.example.org
+PassCmd "password-command 2"
+SSLType IMAPS
+User home.manager.jr
+
+IMAPStore hm-account-remote
+Account hm-account
+
+MaildirStore hm-account-local
+Inbox /home/hm-user/Mail/hm-account/Inbox
+Path /home/hm-user/Mail/hm-account/
+SubFolders Verbatim
+
+Channel hm-account
+Create None
+Expunge None
+Master :hm-account-remote:
+Patterns *
+Remove None
+Slave :hm-account-local:
+SyncState *
+
+
+IMAPAccount hm@example.com
+CertificateFile /etc/ssl/certs/ca-certificates.crt
+Host imap.example.com
+PassCmd password-command
+SSLType IMAPS
+User home.manager
+
+IMAPStore hm@example.com-remote
+Account hm@example.com
+
+MaildirStore hm@example.com-local
+Inbox /home/hm-user/Mail/hm@example.com/Inbox
+Path /home/hm-user/Mail/hm@example.com/
+SubFolders Verbatim
+
+Channel hm@example.com
+Create None
+Expunge None
+Master :hm@example.com-remote:
+Patterns *
+Remove None
+Slave :hm@example.com-local:
+SyncState *
+
+
+Group inboxes
+Channel hm-account:Inbox
+Channel hm@example.com:Inbox1,Inbox2