Create Work Item Modal: Issue Description template from Project settings is overridden by default template present in repository
# Summary
Following the steps mentioned in [Description Template Documentation](https://docs.gitlab.com/user/project/description_templates/#set-a-default-template-for-merge-requests-and-issues), when a project has both; Default Template defined within Project Settings **and** a default template within repository as `.gitlab/issue_templates/Default.md` file, Create Work Item modal (currently behind feature-flag `work_items_alpha`) always loads repository default template instead of Project Settings template.

~backend
- [ ] Add a new GraphQL field that returns the template from the project settings. See https://gitlab.com/gitlab-org/gitlab/-/issues/544889#note_2659391197 for more background
```js
query workItemDescriptionTemplatesList($fullPath: ID!) {
namespace(fullPath: $fullPath) {
id
workItemDescriptionTemplates {
projectSettingsTemplate // add the new field here? or maybe `namespaceSettingsTemplate` is a better name?
nodes {
name
projectId
category
}
}
}
}
```
## Expected behavior
As [highlighted](https://docs.gitlab.com/user/project/description_templates/#priority-of-default-description-templates) in our documentation, the following order of priority should be followed;
1. Template set in project settings.
2. Default.md (case-insensitive) from the parent group.
2. Default.md (case-insensitive) from the project repository.
issue