Cross platform improvements

[tracygardner]

Issues found during cross-platform testing.

• On very old iPhones you can't update to a version of iOS that will run Havok physics (WASM SIMD needed). Catch this and add a helpful error banner
• Touch screen joystick wasn't controlling onscreen camera like arrow controls do
• There's a layout issue on some iPhones which makes the canvas buttons large and distorts the canvas (while fine on other iPhones)
• Mac issue with key press releases not emitting which means Ctrl+Z could emit Z continuously, making a character walk forward in AZERTY!
• Colour picker doesn't work on mobile (API not implemented there) but the the error told you to install a different browser.
• Workspace zoom doesn't anchor to top left. This effect is worse on phones but a problem everywhere. (It's the blockly default but doesn't work well for Flock)
• Audio doesn't stop when Flock XR isn't visible. It should.
• Samsung A14 renders black for any material with alpha. Tracked down to bug in WebGL drivers but this is a pretty common phone.
• Windows Firefox 3D pendant appears upside down!!! (Intermittent. Fixes on click on canvas???) Woo - it's a floating point precision combined with quaternion issue! Fun.
• Starter demo - not exactly a bug but really highlights that the bounding box for hover is based on the t-pose of a character and therefore very wide (hover cursor)
• Various demos - help info is keyboard specific and not helpful on mobile
• Shape push - controls move camera and canvas - need to add block to turn canvas controls off
• Forest base - material should be part of the platform (so that when you copy it, the material is copied). May affect other projects.
• When looking at the code in fullscreen landscape mode, the vertical scroll bar is off the screen.
• Firefox layout issues
• Firefox doesn't support Web USB for micro:bit. Need a helpful message.
• Z-ordering issue with UI text input an main menu (see comment below)

[tracygardner]

Helpful error banner for iOS devices on old OS (needs 16.4 or later for Havok physics). 0488b5d

Tested on BrowserStack.

Vs on iOS v17:

[tracygardner]

Black materials on Samsung A14 when alpha used. WebGL driver bug, but a pretty common phone. Turned off uniform buffers which does fix it. But need to watch for any knock on effects.

1c06a1e

[tracygardner]

Reported by a Mac keyboard user. Ctrl+Z on Mac was triggering continuous Z press due to different modifier and key up handling on Mac. Oops. 1c06a1e

[tracygardner]

Colour picker API isn't implemented on mobile and probably won't be. Removed the button on mobile. And adapted the banner for desktop browsers such as Firefox that don't support it. May implement a custom version just for the canvas in future. f449ae7

[tracygardner]

On firefox, the toolbox edge and scroll bar appear over the toolbox which gives a grey line that you don't get in other browsers. Minor.