feat(toolbox): add DESTRUCTIVE button type for hangup button on native

[iospro]

Summary

• Added DESTRUCTIVE button type to IconButton for native, styled with design system danger tokens
• Applied DESTRUCTIVE type to the hangup button, replacing custom color scheme with semantic styling
• Replaced hardcoded hangup color rgb(227,79,86) with ColorPalette.red and BaseTheme.palette.actionDanger

Changes

File	Details
base/ui/components/native/IconButton.tsx	Added DESTRUCTIVE branch: white icon, actionDanger background, darkGrey underlay
base/react/components/native/styles.ts	Added iconButtonContainerDestructive style with actionDanger background
toolbox/components/native/HangupMenuButton.tsx	Changed button type from PRIMARY to DESTRUCTIVE
toolbox/components/native/styles.ts	Hangup button background switched to BaseTheme.palette.actionDanger
base/color-scheme/defaultScheme.ts	Replaced hardcoded rgb(227,79,86) with ColorPalette.red

Motivation

The hangup button is a destructive action — ending a call. Using a generic PRIMARY type with a custom color bypassed the design system. The new DESTRUCTIVE type uses semantic tokens (actionDanger) making the color consistent with other danger actions across the app and easy to theme.

[jitsi-jenkins]

Hi, thanks for your contribution!
If you haven't already done so, could you please make sure you sign our CLA (https://jitsi.org/icla for individuals and https://jitsi.org/ccla for corporations)? We would unfortunately be unable to merge your patch unless we have that piece :(.