Identify and update split button dropdowns that change the default on click - Based on user testing
For better understanding, here are the differences between a "bad" example of a split button and a "good" example of a split button.
| Bad (Deprecated) | Good |
| ------ | ------ |
|  |  |
Based on user testing from https://gitlab.com/gitlab-org/gitlab-services/design.gitlab.com/-/issues/681, the "changing default" button is not the expected behavior. We have deprecated this "changing default" button behavior for split buttons [in Pajamas](https://design.gitlab.com/components/button#split-dropdown). They also do not follow our standard split buttons, which take action immediately when clicking an option in the dropdown.
Each instance below should be updated to the expected behavior (taking action immediately on click), or be redesigned to use a different method.
| Instance | Screenshot | DRI | Issue/Epic to update |
| ------ | ------ | ------ | ------ |
| Create merge request dropdown - Issue |  | Holly | https://gitlab.com/gitlab-org/gitlab/-/issues/333146 |
| Issues dashboard. Uses `shared/new_project_item_select` |  | Holly | https://gitlab.com/gitlab-org/gitlab/-/issues/333147 |
| Merge requests Dashboard. Uses `shared/new_project_item_select` |  | Mike Nichols | https://gitlab.com/gitlab-org/gitlab/-/issues/333147 |
| Milestones Dashboard. Uses `shared/new_project_item_select` |  | Holly | https://gitlab.com/gitlab-org/gitlab/-/issues/333147 |
| Group/Merge requests - Empty state. Uses `shared/new_project_item_select` |  | TBD | https://gitlab.com/gitlab-org/gitlab/-/issues/333147 |
| Comment/Start a thread |  | Holly/Pedro | https://gitlab.com/groups/gitlab-org/-/epics/4943 |
| Web IDE/GitPod - Project page |  | Michael Le | https://gitlab.com/gitlab-org/gitlab/-/issues/333148 |
**Note:** Most of the examples above use a shared file `= render 'shared/new_project_item_select`, in which you select a project from the dropdown, then take action. This file can be adjusted at the source.
epic