Signed-off-by: NDmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Instead of an integration test that creates 101 Todo records to test a
simple view helper, just unit test the helper.

Use the EnforcedStyleForMultiline: no_comma option.
Signed-off-by: NRémy Coutable <remy@rymai.me>

Improved todo message when an issue is assigned to yourself.
- The new message when an user assign to himself an issue or a mr is: "You
assigned issue xx to yourself"
- The new message when an user adds a todo to himself is: "You added a
todo for issue xx"
- The new message when and user mention himself is: "You mentioned
yourself on issue xx"
- The new message when an user directly address himself is: "You
directly addressed yourself on issue xx"
- The new message when an user mark himself as an approver is: "You set
yourself as an approver for merge request xx"

This reverts merge request !10076

Added the option to filter todo by Added and Pipelines

Moved if statements around in view

Closes #24127

We’re being kept up to date the counter data but we’re not using it.
The only thing which is not real if is the number of projects that the 
user read changes the number of todos can be stale for some time.

The counters will be sync just after the user receives a new todo or mark any as done

- As todos are created/updated inside the TodoService
we repopulate the cache just there for both pending/done todos
- Todos as mark as done from the TodosController we update cache
there too
- All the added methods are kept in the User class for cohesion

Based on feedback from !4502

This reverts commit 13e37a3e.