Allow user to choose email address when creating commits via web operations

[eduardosm]

Feature Description

Some users might not want to use the same email address for commits and notifications.

When a user has multiple email addresses, GitHub allows to choose which one to use when merging PRs or editing files via web (screenshot below). It would be nice to have this feature in Gitea instead of always creating commits with the primary (i.e., notifications) email address.

Screenshots

[wxiaoguang]

-> Support choose email when createing a commit via web UI #33432