feat: center image zooming on the cursor

[mini-bomba]

Description

This PR makes the image zooming via double-click or mouse wheel centered on the cursor position rather than the center of the image.
Clicking the zoom % label (between + and - buttons) now resets the image zoom and pan.
Zooming was also changed from being additive to multiplicative, which makes the "zooming speed" feel consistent.

In the process of doing this I merged the zoom and pan state into one, making it possible to change them at the same time.
The setPan and setZoom functions were recreated for compatibility. resetTransforms was added for convenience.
handleWheel was moved from the ImageViewer into the image gestures hook.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings

AI disclosure:

• Partially AI assisted (clarify which code was AI assisted and briefly explain what it does).
• Fully AI generated (explain what all the generated code does in moderate detail).

[7w1]

Lgtm other than that 1 optional comment

[7w1]

lgtm