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.

Previously, the AudioProcessorPlayer would always match the
AudioProcessor's bus configuration to the requested bus configuration,
even if the processor did not explicitly support the requested
configuration.

Now, if the requested configuration has one or fewer input channels, the
AudioProcessorPlayer will attempt to find a multi-input channel layout
for which `checkBusesLayoutSupported` returns true, and will use such a
layout if it exists. Otherwise, as a last resort, it will fall back to
using the channel layout requested by the AudioProcessorPlayer.

If the AudioProcessorPlayer has no input channels, but the wrapped
processor is initialised with multiple input channels, each of these
inputs will be fed with silence.

If the AudioProcessorPlayer has a single input channel, but the wrapped
processor is initialised with multiple input channels, each input
channel will be fed with a copy of the AudioProcessorPlayer's mono
input.

- Added a new URL::createInputStream() overload that takes an InputStreamOptions helper class to simplify stream creation.
  - Modified the internals of URL and WebInputStream so that parameters are only added to the request body when ParameterHandling is set to inPostData. This allows POST data to be added via URL::withPOSTData() and sent with URL-encoded parameters.

This fixes BadWindow errors from Expose events that may be processed after the window is destroyed.

Ardour seems to listen to the bounds of the plugin window, and will call
`onSize` on the plugin editor when move/resize events are sent to the X
window - even if the size of the window didn't really change. This can
result in an infinite resize loop, where calling `onSize` on the VST3
instance sends a resize event to the plugin window, and this event
causes Ardour to call `onSize` on the plugin view.

To get around this, the Linux ComponentPeer will no longer request a
bounds change from the window system if the requested bounds are the
same as the current bounds.

When normalisation is disabled, the Convolution will now adjust the gain
of the IR using the ratio of the source and destination sampling rates.
This should keep the output level constant when the Convolution's
sampling rate is changed.

This patch also moves PluginHostType into juce_audio_processors in order
to allow hiding of function implementations.

Reports the correct host name for Apple hosts on M1 which host plugins
in a separate process.

Affected hosts are:
- Logic Pro
- GarageBand
- MainStage
- Final Cut Pro