Fix: Graph titles for Delta Report performance tests

Fix: Graph titles for Delta Report performance tests

The title for following performance tests are incorrectly handled when saving to the Delta performance CSV file because of the presence of comma (,) in the title causing blank graphs to be generated.

- Delta b/w 2 anchors, w/o grouping all descendants
- Delta b/w 2 anchors, w/o grouping direct descendants
- Delta b/w 2 anchors, w/o grouping no descendants
- Delta b/w anchor & JSON, w/ grouping all descendants
- Delta b/w anchor & JSON, w/ grouping direct descendants
- Delta b/w anchor & JSON, w/ grouping no descendants

Removed all special characters from graph titles.

Isse-ID: CPS-3185
Change-Id: Iad75788e7dd9f0889c756f31097ce305622684ba
Signed-off-by: Arpit Singh6 <AS00745003@techmahindra.com>