[CA-137573]: Fix "Unrecognised bus type" VDIs.

Use "device/subsystem" to obtain SCSI details of the host CDROM drive.

Signed-off-by: Siddharth Vinothkumar <siddharth.vinothkumar@citrix.com>
Reviewed-by: Chandrika Srinivasan <chandrika.srinivasan@citrix.com>
Imported-by: Siddharth Vinothkumar <siddharth.vinothkumar@citrix.com>

(cherry picked from commit 6ad534df70013f8f24dbf3f7d646694f606702a6)
CP-8744:  SR trim limited to compatible SRs

Limited SR trim capability to LVHD based SRs. Also error handling
was modified to return a XML string response on failure containing
errcode and errmsg as a key value pair. Trim functionality was
separated from the trim plugin entry point.

Signed-off-by: Vineeth Raveendran <vineeth.thampi@citrix.com>
Reviewed-by: Mate Lakat <mate.lakat@citrix.com>

GitHub: closes #182 xapi-project/sm
CP-8744: [UnitTest] Add unittest for trim plugin

Signed-off-by: Mate Lakat <mate.lakat@citrix.com>
Reviewed-by: Vineeth Raveendran <vineeth.thampi@citrix.com>
CA-134864: Fix plugin-call for SXM.

Signed-off-by: Siddharth Vinothkumar <siddharth.vinothkumar@citrix.com>
Reviewed-by: Chandrika Srinivasan <chandrika.srinivasan@citrix.com>

GitHub: closes #173 xapi-project/sm
CP-8657: Remove iSL references from storage manager.

- Removed all code references
- Removed all CSLG error codes
- Replaced CSLGXMLParse to XMLParse

Signed-off-by: Siddharth Vinothkumar <siddharth.vinothkumar@citrix.com>
Reviewed-by: Chandrika Srinivasan <chandrika.srinivasan@citrix.com>

GitHub: closes #183 xapi-project/sm