LUDOC-456 misc: Update the xml ids in BenchmarkingTests.xml

LUDOC-456 misc: Update the xml ids in BenchmarkingTests.xml

This patch updates the xml:id for each section to be a meaningful
name.  Other pages using those ids were also updated accordingly.

The patch also reformats the code to adhere to the 80 cols limit.

Signed-off-by: Joseph Gmitter <jgmitter@whamcloud.com>
Change-Id: I2c880ef7657e4bd9287a2e2596d8dbdc461f8ebe
Reviewed-on: https://review.whamcloud.com/36047
Tested-by: jenkins <devops@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>