[v7.0/forgejo] Add optional pronoun field in user settings (#3076)

**Backport:** https://codeberg.org/forgejo/forgejo/pulls/1518

An attempt at adding an optional pronoun field for user profiles, as suggested here 3 years ago: https://github.com/go-gitea/gitea/issues/13990

![A Forgejo profile showing pronouns to the right of the user's username](/attachments/2e5ff300-d333-46db-9074-f030f199843c)

I made this for [my own instance](https://git.gay/h) and didn't initially think I'd make a PR because of the previous closed issue, but I thought I'd ask the Forgejo matrix chat to see if there was any support and there was!

I'm told I should make a database migration, some help as to how to do that would be appreciated.

Co-authored-by: hazycora <hazysu@riseup.net>
Co-authored-by: Gergely Nagy <forgejo@gergo.csillger.hu>
Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/3076
Reviewed-by: Earl Warren <earl-warren@noreply.codeberg.org>
Co-authored-by: forgejo-backport-action <forgejo-backport-action@noreply.codeberg.org>
Co-committed-by: forgejo-backport-action <forgejo-backport-action@noreply.codeberg.org>

options/locale/locale_en-US.ini

@@ -705,6 +705,9 @@ password_username_disabled = Non-local users are not allowed to change their use
 full_name = Full name
 website = Website
 location = Location
+pronouns = Pronouns
+pronouns_custom = Custom
+pronouns_unspecified = Unspecified
 update_theme = Change theme
 update_profile = Update profile
 update_language = Change language