[RTADPA BW Tests] Fixes to get 'comparisons' up and running again

Addressing from lhcb-datapkg/PRConfig#14 (closed):

• hlt2_and_spruce replace $${process}__comparison$$ in {process}__index.html too. see: !275 (comment 7557836)
• hlt2_and_spruce upload {process}__index too. see: !275 (comment 7557835)

Goes with lhcb-datapkg/PRConfig!383 (merged)