Enabling the hardened runtime also enables library validation, which
means that the manifest generator may not be able to load the built
plugin if the generator runs before the signing step.

The manifest generator tools should not be distributed/archived, so
disabling the hardened runtime for these targets is appropriate.

- added unit tests
- best performance timers used for each platform
- fixed an issue in which timer callbacks could drift

This reverts commit 82377a787a.

Reintegrates changes from cf9fc84669

Similar code was incorrectly removed in
070a6b35e9.

When using CLion to invoke CMake, using a Clang toolchain and Ninja, and
targeting x64, CLion will pass -m64 in CMAKE_C_FLAGS and
CMAKE_CXX_FLAGS. The compilers are passed through to the juceaide build,
but the target arch was not, which meant that the linker attempted to
link x86 libraries, which failed.

This fixes an issue where the app icon would not be visible for
standalone plugin targets.

- Created a new detail namespace
- Moved shared module implementation details into the detail namespace
- Split dependencies so source files only rely on details in the detail namespace
- Removed all code from the juce_gui_basics.cpp file

In order to display a WebKit based webview a plugin will deploy a
temporary standalone executable on the system and host the WebKit
instance inside that.