Previously, updating the program or bypass parameter could cause an
out-of-bounds access into the parameter value cache. This is because
AudioProcessorParameter::getParameterIndex() was used to index into the
cache, but the parameter index could be negative for parameters that
had not been added to the AudioProcessor.

We now use the appropriate index in the cache for parameters that
have not been added to the AudioProcessor.

This fixes a bug when creating a TextLayout with whitespace at the start of lines.

See the breaking changes document for more details.

On some Linux distros, the audio settings dialog was opening with the
wrong size and position. The culprit seems to be the call to setSize()
which was called inside resized(). We now try to avoid calling setSize()
if we would do so inside a resized() call.

Sometimes, changing the bounds of the window inside the DPICHANGED
handler can cause further DPI change events to be processed. Previously,
the scaleFactor set by the "inner" events was also being used when
notifying listeners about the "outer" events, leading to graphical
glitches.

An effect of the bug was that VST2 views in the AudioPluginHost would
occasionally render with an incorrect size and position after dragging
them between displays with different scale factors.

With this change in place, we only notify listeners and update window
bounds once there are no DPI changes in progress.