Add showTools prop to Tldraw to control visible toolbar tools

[KDSBrowne]

This PR introduces a new showTools prop for the Tldraw component that allows specifying which shapes and tools should be displayed on the toolbar.

If showTools is not provided, all available shapes and tools will be shown by default.

Example usage:
<Tldraw showTools={['list', 'of', 'tools', 'to', 'show']} />

Available tools/shapes:

select,
hand,
highlight,
draw,
eraser,
arrow,
text,
note,
rectangle,
ellipse,
diamond,
triangle,
trapezoid,
rhombus,
hexagon,
cloud,
star,
oval,
x-box,
check-box,
arrow-left,
arrow-up,
arrow-down,
arrow-right,
line,
frame,

Related to:
bigbluebutton/bigbluebutton#22857