Qt6 (#669)

* update qt6 upgrade progress

* add flawed addition for QRenderTarget and link needed libs

* update to better logging format

* move many assets and qml files into qrc

* get rid of deprecation messages

* remove additional deprecation notices

* make Qt6 finally render on desktop with some progress on vr

* initialize QRhi with QQuickRenderControl

* use default values to stop SegFaults

* fix compilation on windows

* add windows files for aiding in running exe

* fix formatting of testing qt.conf

* first attempt on using textures instead of files in AudioTabController

* Fix public/private access issue

---------

Co-authored-by: RTUnreal <unreal@rtinf.net>

build_scripts/win/env.ps1.in

@@ -0,0 +1,5 @@
+if ($null -ne $env:_SAVED_PATH) {
+    $env:PATH=$env:_SAVED_PATH;
+}
+$env:_SAVED_PATH=$env:PATH;
+$env:PATH+=";@NATIVE_QT_ROOT@\bin;@NATIVE_PROJECT_SOURCE_DIR@\third-party\openvr\bin\win64";

build_scripts/win/env.sh.in

@@ -0,0 +1,9 @@
+export _SAVED_PATH="${_SAVED_PATH:-}"
+if [ ! -z "$_SAVED_PATH" ]; then
+    export PATH="$_SAVED_PATH"
+fi
+export _SAVED_PATH="$PATH"
+export PATH="$PATH:$(echo "@NATIVE_QT_ROOT@"|sed -E 's/(\w):/\/\L\1/')/bin:$(echo "@PROJECT_SOURCE_DIR@"|sed -E 's/(\w):/\/\L\1/')/third-party/openvr/bin/win64"
+
+echo $_SAVED_PATH
+echo $PATH

build_scripts/win/qt.conf.in

@@ -0,0 +1,2 @@
+[Paths]
+Plugins=@QT_ROOT@\\plugins