Co-authored-by: LeonPS <leonps531@gmail.com>

While improving Android IME support (da38c1ed), text editor destructors
were updated to explicitly pass keyboard focus elsewhere.
As far as I remember, the change was intended to prevent the text input
system from trying to send input events to components while they were
being destroyed, in which case the TextInputTarget and Component bases
may be 'valid', but the data members referenced by the TextInputTarget
implementation may have been destroyed.

The motivation for removing these lines is that giving away focus and
sending a focus event can cause all components to become unfocused. This
is problematic in the case of slider text editors - pressing 'enter'
will cause the TextEditor to be destroyed, but the parent component will
fail to gain focus, so pressing 'tab' will not have any effect.

Running under Gnome, calling ComponentPeer::forceSetBounds immediately
after creating a new peer causes the peer to emit a visibility-changed
event because the window manager sometimes reports that the new window
is in IconicState.

_NET_WM_STATE_HIDDEN seems to more accurately reflect whether the window
is really minimised or off-screen.

- macOS behaviour of setRealtime now matches other platforms

MR feedback

Using a preferred channel config with no input or output channels could
cause an assertion here because the AudioProcessor will always have a
single input/output bus by default.