[25454] Make draw area expand horizontally and improve axis rendering

[raulojeda22]

Description

• Allow the draw area to grow horizontally with the window; the shape movement bound (maxX) now tracks the draw aread width and published shapes are dragged back inside when the window shrinks
• Draw the coordinate axis arrows and labels using the theme foreground color instead of hardcoded black, so they are visible in dark mode
• Remove redundant outer frame around the draw area
• Remove the unused bottom tool bar

Contributor Checklist

• Commit messages follow the project guidelines.
• Changes do not break current interoperability.
• New feature has been documented/Current behavior is correctly described in the documentation.
• Applicable backports have been included in the description.

Reviewer Checklist

• The PR has a milestone assigned.
• The title and description correctly express the PR's purpose.
• Check contributor checklist is correct.
• CI passes without warnings or errors.

[zesk1999]

It looks nicer now!
What would be worth checking is that maxX is now a variable that can change the value and it is being accesses from 2 threads where in one of them it is not protected (before there was no need since it was fixed). I suggest making it atomic or incorporating it into mutex.

[zesk1999]

Can we use mp_SD instead since they seem to be equal throughout the code?