FE: Extend group_projects_dropdown.vue with new options

Why are we doing this work

In order to better re-use group_projects_dropdown.vue

Couple of extra properties needs to be added:

fullPayload: when set to true, dropdown should emit not only selected id but full project.

multiple: now it is set multiple by default, related issue requires single selection, we need to provide option to enable/disable multiple option.

Relevant links

Non-functional requirements

• Documentation:
• Feature flag:
• Performance:
• Testing:

Implementation plan

1. Add required props to group_projects_dropdown.vue
2. Add test coverage

Verification steps

1. It is possible to use different states of component with new properties