Builder should not be a valid parameter for stats dashboard
https://bugs.webkit.org/show_bug.cgi?id=106698

Reviewed by Dirk Pranke.

Since builder is a dashboard specific parameter, dashboard_base
should not be handling it in handleValidHashParameterWrapper, rather,
each specific dashboard should in its handleValidHashParameter function.

Note that the FIXME in dashboard_base about this was actually wrong -
we don't want to move it to g_crossDashboardState, because it isn't
actually cross dashboard state.

In fact, flakiness and treemap have the code in
handleValidHashParameter, but it is currently dead code because
dashboard_base gets to it first.

Added the proper handling to timeline_explorer, since builder is
valid there.

* TestResultServer/static-dashboards/dashboard_base.js:
* TestResultServer/static-dashboards/timeline_explorer.html:


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@139522 268f45cc-cd09-0410-ab3c-d52691b4dbfc