Fix profiling of QML/JS compilation

Fix profiling of QML/JS compilation

The compilation of .js resources was missed and the compile times were
underestimated because the dependency resolution and error checking
wasn't factored in. In particular we only profiled the done() step for
QQmlTypeData. However, JavaScript compilation also occurs in the
dataReceived() step of QQmlScriptBlob and QQmlTypeData will already
parse the program into an AST at that step.

Compile steps can be nested now, but considering the fact that
significant time may be spent before and after compiling dependencies
for a parent module, this seems to be the best way to model them.

Furthermore, in order to not needlessly convert QUrl to QString at
runtime, the compilation profiler saves the files now as QUrl.

Change-Id: I215a87787f9117c069ecd77b2d913cc0b0ff3c89
Reviewed-by: Simon Hausmann <simon.hausmann@theqtcompany.com>