Consider moving translations from `MRAppovals|` and `MRDiff|` to `MergeRequests|`
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### Proposal
Move translations related to merge requests to the `MergeRequests|` namespace, there are around 5-7 of them:
```pot
msgid "MRApprovals|Approvals"
msgstr ""
msgid "MRApprovals|Approved by"
msgstr ""
msgid "MRApprovals|Approvers"
msgstr ""
msgid "MRDiff|Show changes only"
msgstr ""
msgid "MRDiff|Show full file"
msgstr ""
```
**Why?** We can reduce the complexity of our application translations. Namespaces act to give context for translations and I think that a "MergeRequests" context is helpful for translators.
More info at: https://docs.gitlab.com/ee/development/i18n/externalization.html#namespaces
### Original Discussion
The following discussion from !38136 should be addressed:
- [ ] @mrincon started a [discussion](https://gitlab.com/gitlab-org/gitlab/-/merge_requests/38136#note_394531738): (+1 comment)
> **Suggestion (non-blocking):** I think the `MRApprovals|` namespace is far too small (only 2 entries plus this one). Is it possible we start using `MergeRequests|` instead?
>
> **Note:** Seems `MRDiff` is in a similar state.
issue