[reports][js] fix showing exp table according to report status

The experiments tables will show properly according to report
status and group count. If a report is locked/published and has
only 1 group, only the group's experiment table will be shown.
Otherwise, both the main experiments table and the per-group
experiment tables will be shown.

Closes #527
1 job for 527-report-single-group-exp-table in 14 minutes and 47 seconds (queued for 4 seconds)
Status Job ID Name Coverage
  Build
passed #168566
docker-build
build_linux_36

00:14:47

67.0%