Allow a Dimension::Fit to extend beyond the terminal maximum height (#950)

For long tables (and other DOM elements), one may want the screen to render on dimensions higher than the terminal.  
Hence, this PR proposes a way to do so, with an optional parameter in the `Dimension::Fit` util function.

Discussions / Issues :  
- https://github.com/ArthurSonzogni/FTXUI/issues/572
- https://github.com/ArthurSonzogni/FTXUI/discussions/949

Bug:https://github.com/ArthurSonzogni/FTXUI/issues/572
Fixed:Bug:https://github.com/ArthurSonzogni/FTXUI/issues/572


Co-authored-by: ArthurSonzogni <sonzogniarthur@gmail.com>