RESTWS-941: Any authenticated user should be able to read available modules

[ibacher]

Description of what I changed

This changes the ModuleResource class so that read-only requests (GET and search) are available to any authenticated user and not just those with the "Manage Modules" privilege.

Issue I worked on

see https://issues.openmrs.org/browse/RESTWS-941

Checklist: I completed these to help reviewers :)

• My IDE is configured to follow the code style of this project.

  No? Unsure? -> configure your IDE, format the code and add the changes with git add . && git commit --amend

• I have added tests to cover my changes. (If you refactored
  existing code that was well tested you do not have to add tests)

  No? -> write tests and add them to this commit git add . && git commit --amend

• I ran mvn clean package right before creating this pull request and
  added all formatting changes to my commit.

  No? -> execute above command

• All new and existing tests passed.

  No? -> figure out why and add the fix to your commit. It is your responsibility to make sure your code works.

• My pull request is based on the latest changes of the master branch.

  No? Unsure? -> execute command git pull --rebase upstream master

[coveralls]

coverage: 47.126% (-0.003%) from 47.129%
when pulling 1d49014 on RESTWS-941
into 58cc4a9 on master.