Web Inspector: [Styles] Implement navigation to UI locations of property names/values in the source code
Relanding fixed r144449.
https://bugs.webkit.org/show_bug.cgi?id=105285

Reviewed by Vsevolod Vlasov.

Users can now Ctrl/Cmd-click CSS property names/values whose UI locations are found in
an external stylesheet/sass/other file. Inline stylesheets are not navigable,
since their start position is not detectable inside the surrounding HTML as of yet.

No new tests, a UI change.

* inspector/front-end/CSSStyleModel.js:
(WebInspector.CSSRule.prototype.isSourceNavigable): Whether the rule contains reliable source code information.
(WebInspector.CSSProperty.prototype.uiLocation): Returns a UILocation for the property name of value.
* inspector/front-end/StylesSidebarPane.js: Add navigation code.
(WebInspector.StylesSidebarPane.prototype._innerRebuildUpdate):
(WebInspector.StylePropertiesSection):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@144451 268f45cc-cd09-0410-ab3c-d52691b4dbfc