[ICAT] Fix endpoint issue

[mantid-builder]

Original Reporter: Jay Rainey

This ticket is blocks : TRAC7636

Although the end-point is set in Facilities.xml it is in fact not used in ICat4Catalog or other catalogs. As it is not used, the gSoap generated files see the related soap_endpoint as being empty, and use the endpoint the files were generated against. As such, we want to set this end-point accordingly.

To do this we need to:

1. Update catalogLogin to contain a list of all available facilities.

2. Update catalogLogin to obtain the soap-endpoint based on the facility selected, and then pass it to the related catalog login method.

3. Update all catalogs (ICat4Catalog & ICat3Catalog) to set the end-point for the session in the login method, and then use the session class to "get" the end-point & use it throughout.

   Keywords: ICAT

[mantid-builder]

This issue was originally trac ticket 8581