Initial clean-up of the SOAP messaging facilities

Description

This MR consists in a first initial clean-up of the SOAp messaging facilities. In particular,

• the GEMSOAPToolBox class is removed and its methods included in the gem::utils::soap namespace;
• the common xdata::soap::Serializer class is used to serialize the SOAP messages parameters;
• the extraction of SOAP parameters from a message is templatized to be compatible with all xdata types.

In addition,

• the include directives have been ordered in all touched files;
• the legacy CfgType and RunType parameters have been deleted.

Related Issue

This MR is part of the first cleaning steps for #170 and #171.

How Has This Been Tested?

SOAP messages can still be sent are received, successfully starting a run is still possible.

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.