Fix search for ENGIN-X files in the instrument data cache

[GuiMacielPereira]

Describe the bug
The search for files in the data cache is not working for Engin-X files.
This is because when we query the instrument from the config service in Mantid, it comes back as ENGIN-X, with an hyphen, while the path in the data cash is built without an hyphen, ENGINX.

Expected behavior
The path to ENGINX files is correctly found.

[GuiMacielPereira]

This discrepancy is due to ENGINX being the only instrument in the data cache using the short form of the instrument name, while all of the other instruments use the long form. I asked the IDAaaS team if they could change this so that all instruments use the long version, i.e. change ENGINX to ENGIN-X

[GuiMacielPereira]

The previous work fixed part of this issue so that the correct index file /data/instrument/ENGINX/ENGINX_index.json is found but I am re-opening it because the path that is returned still contains the name ENGIN-X instead of ENGINX. This means that the search for ENGINX files is still failing in the data cache. Somehow we didn't catch this before, probably because we didn't have the necessary permissions.