Qbs: pass provider args if QbsDeps was run

[ABBAPOH]

Changelog: Feature: Qbs helper now invokes Conan provider automatically.
Docs: Omit

Now Qbs helper passes required arguments for the "conan" provider to qbs if QbsDeps was run.

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[memsharded]

Minor naming issue: When we talk about "Qbs Toolchainit should be aQbsToolchainspecific generator that is intended to generate files related to the current settings and options (not dependencies likeQbsDeps). The Qbs`` is not called a toolchain generator is typically called the "Qbs" helper or wrapper.