Update select location workflow for Piece creation/edit

Overview: After discussing this issue we have concluded that the best solution will be to update the workflow for create item and select location. This will provide a more permanent solution for Goldenrod release

Approach:

• Remove the need for the "Add item" plugin by implementing a toggle that allows the user to tell FOLIO when to automatically create an item record for the piece.
• Update location selection to simplify user experience and prevent system errors

Acceptance criteria:
1)
Given user is creating a piece
When the POL has only 1 location
Then location is pre populated in select location field

2)
Given user is creating a piece
When the POL MORE than 1 location
Then select location is a select list with all locations from POL

3)
Given user is creating a piece
When the use does not want to use a location from POL
Then user can click "Assign a different location"
AND Location modal appears

4)
Given clicks "Assign a different location"
When selecting a location in the modal and clicking save and close
Then locations is added to select location field
AND location can be cleared by clicking the 'x'