Soft delete issuables
Fixes#2489
What still needs to happen: research on the indexes, the gem suggests a [lot of changes](https://github.com/rubysherpas/paranoia#about-indexes) though this is probably a good idea to discuss and I'm unsure on the impact of an omnibus upgrade as I suspect creating about 10 new indexes has a large impact on the downtime.
TODO:
- [x] Also group owners can ***soft*** delete
- [x] Button should be hidden
See merge request !2982
Ability to move issue to another project
Tasks:
- [x] Create scaffold of service that will move issue to another project.
- [x] Close old issue, add system note about moving issue to a new project.
- [x] Create a new issue, add system note about issue being moved from old project.
- [x] Check if issue can be moved to another project before executing service
- [x] Check permissions when moving an issue (`:admin_issue` ability)
- [x] Display select box for a new project when editing an issue
- [x] Show only projects that issue can be moved into in that select box
- [x] Add project select handler, helper and some permission filters to it
- [x] Preserve as much information as possible, including author
- [x] Prepare mechanisms that unfolds local references in issue description
- [x] Rewrite issue description with references unfolding and add some specs for it
- [x] Rewrite all system notes and comments attached to issue that is being moved
- [x] Update `Label` so that is was able to create cross reference labels (separate MR)
- [x] Add notifications about moving issue to another project
- [x] Display confirmation alert/message when issue move has been requested
- [x] Make it possible to undo selecting project where issue will be moved to
- [x] Add column to issue, that will indicate if it has been moved to another project
- [x] Do not allow to move issue that has been already moved
- [x] Write top-to-bottom feature spec in RSpec instead of Spinach
UI:


Closes#3024
See merge request !2831
Trigger a todo for mentions on commits page
Closes#14006
* Screenshot:

See merge request !3262
External Users
The user has the rights of a public user execpt it can never create a project, group, or team. Also it cant view internal projects.
Partially fix for both #4009 and #13938 (except the LDAP sync or a pattern to detect external users)

See merge request !3171
Bring from EE: Share Project with Group
- [x] Models and migrations
- [x] Logic, UI
- [x] Tests
- [x] Documentation
- [x] Share with group lock
- [x] Api feature
- [x] Api docs
- [x] Api tests
Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
For #12831
cc @DouweM @rspeicher @vsizov
See merge request !3186
It's unclear how these blank values got added, but GitLab.com had a few:
```
irb(main):002:0> Note.where("line_code IS NOT NULL AND line_code = ''").count
=> 439
```
We've added a migration to convert any existing records to use a NULL
value when blank, and updated Note to set blank values to nil before
validation.
This allows the LIKE condition to use an index. Without a GIN + trigram
index LIKE queries using a wildcard at the start _won't_ use an index
and instead perform a sequence scan.
The only major difference with the EE version is the change from a light and dark logo to only a header logo
The dark logo wasn't used anyway, so it seemed to make sense to me to rename the field to the actual function of it
Add an option to supply root email through an environmental variable.
_Originally opened at !2499 by @3kami3._
---
Add an option to supply root email through an environmental variable.
See merge request !2751