Splitting and cleanup of the AMC13 applications

Description

This MR implements the following clean up actions:

• Move the AMC13Readout application in the gem::readout namespace
• Move the AMC13Manager application into the gem::hardware namespace

It was also noticed that not all struct fields in the example xDAQ configuration were matching the application names. Fixing it.

Related Issue

Addresses the first part of #46 (closed), i.e. moving the AMC13Readout application into the gem::readout namespace.

How Has This Been Tested?

Applications can still be launched.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.