Add 0-suffixed fields to GetIdentity.

The function is also used in GetIdentitiesByScore. Addresses bug #5729.
Fix missing Identity fields in GetIdentitiesByScore.
Disallow access to the web interface for users who don't have full access to the node web interface:
- Register the Toadlets with fullAccessOnly==true so their menus get hidden when the user does not have access. Notice that this is not sufficient for permission checks, the following is needed as well:
- Check whether full access is allowed in the WebInterfaceToadlet and the implementors so WOT can be used with a node which is in public gateway mode.
Remove useless function overrides. They are probably legacy from when there was no super implementation.
Fix missing Identity field in GetIdentity.

Also moves adding the Identity field into the field-adding function.
Merge branch 'issue-5729' of https://github.com/Thynix/plugin-WoT-staging into Thynix-issue-5729
Re-order parameters to have the standard order used in the whole codebase:
First the truster, then the trustee.
Notice that this stresses the "flow of trust" *from* the truster *to* the trustee.
Cache what is used twice, not what is used only once anyway.
Split up addIdentityFields into addIdentityFields, addTrustFields and addScoreFields:
- The old code did cause the call to addIdentityFields in handleGetIdentitiesByScore to re-query the Score object even though it was already known in handleGetIdentitiesByScore. This would have been a severe performance issue since handleGetIdentitiesByScore is heavy anyway.
Document why we duplicate the FCP reply - to provide a legacy interface
- Also, reorder the code to have the non-legacy stuff at first.