DevTools: [CSS] eliminate usage of ruleId in setRuleSelector method

This patch modifies CSS domain of devtools remote debugging protocol.
Instead of using ruleId for addressing rule, method setRuleSelector
now accepts styleSheetId and sourceRange, which should describe
coordinates of the selector to changed.

With this patch in place, styleId and ruleId types are no longer used
in protocol. They will be eliminated in the follow-up.

BUG=341506
R=apavlov@chromium.org, pfeldman@chromium.org

Review URL: https://codereview.chromium.org/208153002

git-svn-id: svn://svn.chromium.org/blink/trunk@170853 bbb929c8-8fbe-4397-9dbb-9b2b20218538