[devtools] Remove trailing fragment identifier from script urls

Scripts should be identified by resource and text range.
Fragement identifiers on urls may cause URLs for the same
resource to not match. Therefore: if the URL supplied to ScriptSourceCode has a fragment identifier, remove it.
    
Add LayoutTest for inlined-script breakpoints with fragment id.


BUG=306239

Review URL: https://codereview.chromium.org/26538007

git-svn-id: svn://svn.chromium.org/blink/trunk@162138 bbb929c8-8fbe-4397-9dbb-9b2b20218538