Merge #3175

3175: Rename dump command from --dumps-dir to --dump-dir r=dureuill a=dureuill

# Pull Request

## Related issue
Fixes #3132 

## What does this PR do?
- Rename the dump commands, env variables and default config

## PR checklist
Please check if your PR fulfills the following requirements:
- [x] Does this PR fix an existing issue, or have you listed the changes applied in the PR description (and why they are needed)?
- [x] Have you read the contributing guidelines?
- [x] Have you made sure that the title is accurate and descriptive of the changes?

Thank you so much for contributing to Meilisearch!


Co-authored-by: Louis Dureuil <louis@meilisearch.com>

meilisearch-http/tests/common/server.rs

@@ -184,7 +184,7 @@ impl Server {
 pub fn default_settings(dir: impl AsRef<Path>) -> Opt {
     Opt {
         db_path: dir.as_ref().join("db"),
-        dumps_dir: dir.as_ref().join("dump"),
+        dump_dir: dir.as_ref().join("dumps"),
         env: "development".to_owned(),
         #[cfg(all(not(debug_assertions), feature = "analytics"))]
         no_analytics: true,