When immediately closing a MidiInput after starting, the ALSA handle may be closed whilst the MidiInputThread is running and it polls a destroyed handle

This commit partially reverts the changes introduced in 455e08da as having an intermediate HWND and reparenting the plug-in window was causing issues when hosting certain plug-ins such as u-he's Diva and Arturia's Mini V3

The increased border size should make it slightly less fiddly to tap on
the window border.

This patch fixes an issue where calling `updateHostDisplay` with no
argument would have no effect.

For DialogWindow, uses the scale of componentToCentreAround.

This allows drawing dialog windows at the expected scale in plugins.
An associated component must be supplied in order for this to work.

This ensures the function IUnknown_GetWindow is declared in shlwapi.h
when building against the Windows 7 SDK.

This resolves an issue on macOS Catalina when using
JUCE_COREGRAPHICS_DRAW_ASYNC where windows would sometimes fail to
completely repaint when they were unminimized.

This fixes an issue where non-ascii characters in channel and MIDI
device names were not drawn correctly.