Add Location Controller and Tests

[github-actions]

Acceptance Criteria:

• There is LocationController.java file in the src/main/java/edu/ucsb/cs156/spring/backend/controllers directory.
• LocationController.java implements a class that implements an API endpoint that takes in the necessary
  parameters, calls the LocationQueryService, and returns the results.
• The file LocationController.java file make appropriate use of the
  annotations @Tag, @Operation and @Parameter to document the API.
• The controller endpoint shows up on the Swagger UI page.
• There is a LocationControllerTests.java file in the src/test/java/edu/ucsb/cs156/spring/backend/controllers directory.
• The tests in LocationControllerTests provide 100% coverage of LocationController for both jacoco and pitest.

Details

See the assignment description at https://ucsb-cs156.github.io/f23/lab/team01 for details.