Rename "Award emoji" to "Reactions"
## Purpose
The term "Award emoji" is unclear, and is not used consistently alongside the UI. In numerous places we refer to these as "Reactions", such as "Add reaction" on the emoji picker, and "My-reaction" filter.
In https://gitlab.com/gitlab-org/gitlab/-/merge_requests/119463 we removed the toast which previously displayed "award emoji"
Context from [slack](https://gitlab.slack.com/archives/CLW71KM96/p1682976304362509):
> <span dir="">Do you know why we call an emoji reaction to an issue an "award" in the tooltip when you add or remove it? It seems weird. I add </span>:watermelon: <span dir="">to keep track of issues (so I can find them by filtering issues by that icon) and it's definitely not an "award".</span>
> <span dir="">I want it noted that I support your request 10000%. I </span>**really**<span dir=""> dislike the “award” verb.</span>
Additional [slack context ](https://gitlab.slack.com/archives/C0259241E/p1682700906649709)where the "award" term made it unclear where to find this functionality.
> <span dir="">does anyone know whether there's an API call to change "emoji reaction" to issue/epic/etc. ? I failed to find any references thus far</span>
## Proposal
- [x] MVC 1 https://gitlab.com/gitlab-org/gitlab/-/merge_requests/120641: Rename all user-facing instances of "award emoji" to "emoji reaction". At a glance this primarily appears to impact docs including:
* https://docs.gitlab.com/ee/user/award_emojis.html
* https://docs.gitlab.com/ee/api/award_emoji.html
* https://docs.gitlab.com/ee/development/fe_guide/emojis.html
- [x] MVC 1.5 https://gitlab.com/gitlab-com/www-gitlab-com/-/merge_requests/127204: Update `data/features.yml`.
- [x] MVC 2: [Rename `/award` quick action to `/react`, retaining `/award` as an alias](https://gitlab.com/gitlab-org/gitlab/-/work_items/411309)
Future consideration: Introduce API alias for "reaction", and update https://docs.gitlab.com/ee/api/award_emoji.html accordingly. Consider deprecating the "award" endpoint in the future.
### Additional considerations
The webhook and API endpoints use the "award" language:
- Emoji webhooks (introduced in https://gitlab.com/gitlab-org/gitlab/-/issues/290773+)
- Emoji reactions API
### Availability and Testing
Regression testing, please make sure `e2e:package-and-test` job is passing.
Ensure updated test coverage in unit/integration/feature tests.
issue