Refactor Component::getTextSelected

[wawuwo]

Hi!

This one refactors the function responsible for determining which text property of a component is clicked:

• obscure Corr arg indirectly coming from Schematic::textCorr is removed
• function body is rewritten in a more clear and easy to understand way
• function is documented
• semantics remain the same.

If something is affected by these changes that would be the "click-on-component-property" behaviour; I checked it before pushing and it looked like it was before.

[ra3xdh]

I have tested this PR. Something works wrong with components having long properties list like library transformer device. Look at the attached screencast. The invisible properties are selected. I am using Qt6.7.0+Wayland.
Screencast_20240523_091320.webm

[wawuwo]

@ra3xdh I've fixed it, that was my mistake: while iterating over component's properties the index number describing current property wasn't increased if the property was hidden. It made the index number "lack behind" and point to a wrong property. The bug was not related to a long properties lists, it could be reproduced with any component: one just had to make a "gap" in properties (i.e. "visible, visible, invisible, visible, visible") and click on any property after the gap.

I hope it'll be OK now! 😎

[ra3xdh]

Thanks for the contribution! Now everything works as expected.