Add option to configure alignment of title and subtitle

Since 4.6.0 the title and subtitle of every page are centered and not left-aligned.

This looks bad when combined with a wider Logo, a Watermark image and WizardStyle Modern because the text is not centered in the window but is instead centered in the space left of the Logo. This makes it look like it is left aligned to the Watermark image.

Please add an option to configure the alignment of title and subtitle.

Edit: This seems to be a result of QTIFW-2995