feat(webgl2): update to beamterm 0.15.0 and add disable_auto_css_resize option

[junkdog]

fixes resize detection for responsive layouts where the container size should determine the canvas dimensions

maybe there's a nicer way of doing this, so i'm leaving it in a draft state for now The nicer way was to make a tiny beamterm release.

as part of updating to the next beamterm release, some examples have been updated:

unicode example: now uses the dynamic font atlas, so everything renders properly

clipboard example: enabled clipboard support for webgl2

[junkdog]

i converted this to a draft because i found out that there's a bug in the atlas generation and how the is_emoji crate was used, causing some non-emoji glyphs to be treated as emoji - so i need make another release.

[orhun]

got it, thanks for the update

[junkdog]

removed some 100-150 lines of url detection/extraction since beamterm 0.15.0 provides Terminal::find_url_at cursor position.