Fix user search by email

[come-nc]

Searching for users to share with by email was broken.
This is due to 2 problems:

1. The subname key for users had the wrong casing subName instead of subname
2. The frontend filtering was active despite not being needed as backend already returns a filtered list

Before	After

@dartcafe Is it safe to rename subName to subname or is used elsewhere? The only instance I could find is https://github.com/nextcloud/polls/blob/master/src/js/store/modules/acl.js#L16 and it looks pretty safe to rename if needed.

[dartcafe]

Renaming the subname seems to be no problem.
As far as I remember, removing the filter removed the highlighting as well, since the match may also occur i.e. with the company name of a contact. But this seems to be no more the case.

[dartcafe]

Just for reference: nextcloud-libraries/nextcloud-vue#6219

[come-nc]

@dartcafe Can this be merged? Should I ask the bot to "backport" to next?

[dartcafe]

Sure, I approved. 😉

[dartcafe]

@come-nc Ah, no, backport not necessary. I did the backport already manually, just forgot to link that.

[come-nc]

@dartcafe Would you consider releasing 7.2.5 so that this fix makes it to the appstore?

[dartcafe]

@come-nc I released 7.2.5 yesterday.