This PR fixes docs and UI to avoid usage of Grafana (Other) integration
which is using old mechanism for alert creation.
1. Rename Grafana (Other) integration to Grafana Alerting Legacy
2. Remove its mentions from docs and correct docs for connection Grafana
Alerting
3. Make AlertManager featured integration and upgrade its description.

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Co-authored-by: Rares Mardare <rares.mardare@grafana.com>
Introduce AlertManager v2 integration with improved internal behaviour
it's using grouping from AlertManager, not trying to re-group alerts on
OnCall side.
Existing AlertManager and Grafana Alerting integrations are marked as
Legacy with options to migrate them manually now or be migrated
automatically after DEPRECATION DATE(TBD).
Integration urls and public api responses stay the same both for legacy
and new integrations.
---------
Co-authored-by: Rares Mardare <rares.mardare@grafana.com>
Co-authored-by: Joey Orlando <joey.orlando@grafana.com>
# What this PR does
This PR fixes the bug when new lines were ignored for the existing
templates
## Which issue(s) this PR fixes
## Checklist
- [ ] Unit, integration, and e2e (if applicable) tests updated
- [ ] Documentation added (or `pr:no public docs` PR label added if not
required)
- [ ] `CHANGELOG.md` updated (or `pr:no changelog` PR label added if not
required)
# What this PR does
## Which issue(s) this PR fixes
## Checklist
- [ ] Unit, integration, and e2e (if applicable) tests updated
- [ ] Documentation added (or `pr:no public docs` PR label added if not
required)
- [ ] `CHANGELOG.md` updated (or `pr:no changelog` PR label added if not
required)
* remove email verification related code
* remove email verification related code
* remove sendgrid callback
* remove sendgrid related code
* remove sendgrid related code
* rename sendgrid app to email
* remove email from built-in channels
* remove email from built-in channels
* remove email from built-in channels
* add email backend: https://github.com/grafana/oncall/pull/50
* add email templater
* add email templater
* convert md to html
* add email settings to live settings
* use task to send email, handle some exceptions to create logs
* remove ERROR_NOTIFICATION_MAIL_DELIVERY_FAILED usage
* add email limit logic
* fix tests
* add docs
* remove old email templates
* remove old email templates
* add template_fields to messaging backend
* add messaging backends templates to public api
* add comment for deprecated fields
* fix test
* fix tests
* disable email by default
* don't retry on SMTPException and TimeoutError
* add tests
* bring email back to public api docs
* return ERROR_NOTIFICATION_MAIL_LIMIT_EXCEEDED
* make template_fields tuple
* build_subject_and_title -> build_subject_and_message
* add one more comment about template deprecation
* use 8 as backend id
* add comment about gaierror and BadHeaderError
* add comment on importing in notify_user_async
* edit oss docs
* use web title template to render alert group verbose name
* remove group_verbose_name from tests
* clean up group_verbose_name
* remove verbose_name from API & plugin
* verbose_name migration
* update verbose name on web title template change
* use long queue for updating verbose name
* use first alert for updating verbose name
* improve batch_ids
* fix update_verbose_name
* post-review fixes
* post-review fixes
* use web title template to render alert group verbose name
* remove group_verbose_name from tests
* clean up group_verbose_name
* remove verbose_name from API & plugin
* verbose_name migration
* update verbose name on web title template change
* use long queue for updating verbose name
* use first alert for updating verbose name
* improve batch_ids