resourceloader: Implement mw.inspect 'time' report

resourceloader: Implement mw.inspect 'time' report

When enabling $wgResourceLoaderEnableJSProfiler, mw.loader gets instrumented
with the following timing values for each of the modules loaded on the page:

* 'total' - This measures the time spent in mw.loader#execute(), and
  represents the initialisation of the module's implementation, including
  the registration of messages, templates, and the execution of the 'script'
  closure received from load.php.

* 'script' – This measures only the subset of time spent in the internal
  runScript() function, and represents just the execution of the module's
  JavaScript code as received through mw.loader.implement() from load.php.

  For user scripts and site scripts, this measures the call to domEval
  (formerly known as "globalEval").

* 'execute' - This measures the self time of mw.loader#execute(), which is
  effectively `total - script`.

To view the report, enable the feature, then run `mw.inspect( 'time' )` from
the browser console, which will render a table with the initialisation
overhead from each module used on the page.

Bug: T133646
Change-Id: I68d1193b62c93c97cf09b7d344c896afb437c5ac