So we can use it for projects

This reflects better that it validates paths instead of a namespace model

Since the namespacevalidator now knows the difference between a
top-level and another path, this could all be handled there.

The first part of a full path needs to be validated as a `top_level`
while the rest need to be validated as `wildcard`

`Project` uses `ProjectPathValidator` which is now a
`NamespaceValidator` that skips the format validation.

That way we're sure we are using the same collection of reserved
paths.

I updated the path constraints to reflect the changes: We now allow
some values that are only used on a top level namespace as a name for
a nested group/project.

This is based on a migration in https://dev.gitlab.org/gitlab/gitlabhq/merge_requests/2073

Rename forbidden child namespaces

These routes seem to be taken

Add cop to blacklist specific tables for `add_column_with_default`

Closes #31293

See merge request !10892

Fix typo

See merge request !11003

Revert "Merge branch 'tc-no-todo-service-select' into 'master'"

See merge request !10997

This reverts merge request !10845

Fix emoji alignment

Closes #31595

See merge request !10993

fix link in health check docs

See merge request !10996

Change from .click -> .trigger('click') to make spec pass

See merge request !10995

Update ldap.md to clarify uid should list the attribute not the value

See merge request !10956

We're going to add another cop that deals with another aspect of
`add_column_with_default`, so we need to separate them.

Avoid plucking Todo ids in TodoService

Closes #30374

See merge request !10845

Resolve "rspec_profiling is enabled for MySQL"

See merge request !10967

Enable RSpec/FilePath cop

Closes #31316

See merge request !10911

Pull preserve into render helpers

See merge request !10986

Use grpc 1.2.5

Closes #31143 and gitaly#197

See merge request !10984

Add video blob viewer

See merge request !10749

Add tests for Oauth::AuthorizationsController

See merge request !10982