CMake: replace Conan with find_package and add find modules

Also, necessarily coupled with this:
* add CMakeLists.txt for vendored libnyquist
* fix SoundTouch header include paths
* move nyq_reformat_aud_do_response function
* handle portSMF headers installed to portsmf or portSMF

Signed-off-by: Be <be@mixxx.org>

cmake-modules/Findsbsms.cmake

@@ -0,0 +1,77 @@
+#[=======================================================================[.rst:
+Findsbsms
+--------
+
+Finds the sbsms library.
+
+Imported Targets
+^^^^^^^^^^^^^^^^
+
+This module provides the following imported targets, if found:
+
+``sbsms::sbsms``
+  The sbsms library
+
+Result Variables
+^^^^^^^^^^^^^^^^
+
+This will define the following variables:
+
+``sbsms_FOUND``
+  True if the system has the sbsms library.
+``sbsms_INCLUDE_DIRS``
+  Include directories needed to use sbsms.
+``sbsms_LIBRARIES``
+  Libraries needed to link to sbsms.
+``sbsms_DEFINITIONS``
+  Compile definitions needed to use sbsms.
+
+Cache Variables
+^^^^^^^^^^^^^^^
+
+The following cache variables may also be set:
+
+``sbsms_INCLUDE_DIR``
+  The directory containing ``sbsms.h``.
+``sbsms_LIBRARY``
+  The path to the sbsms library.
+
+#]=======================================================================]
+
+find_package(PkgConfig QUIET)
+if(PkgConfig_FOUND)
+  pkg_check_modules(PC_sbsms QUIET flac)
+endif()
+
+find_path(sbsms_INCLUDE_DIR
+  NAMES sbsms.h
+  PATHS ${PC_sbsms_INCLUDE_DIRS}
+  DOC "sbsms include directory")
+mark_as_advanced(sbsms_INCLUDE_DIR)
+
+find_library(sbsms_LIBRARY
+  NAMES sbsms
+  PATHS ${PC_sbsms_LIBRARY_DIRS}
+  DOC "sbsms library"
+)
+mark_as_advanced(sbsms_LIBRARY)
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(
+  sbsms
+  DEFAULT_MSG
+  sbsms_LIBRARY
+  sbsms_INCLUDE_DIR
+)
+
+if(sbsms_FOUND)
+  if(NOT TARGET sbsms::sbsms)
+    add_library(sbsms::sbsms UNKNOWN IMPORTED)
+    set_target_properties(sbsms::sbsms
+      PROPERTIES
+        IMPORTED_LOCATION "${sbsms_LIBRARY}"
+        INTERFACE_COMPILE_OPTIONS "${PC_sbsms_CFLAGS_OTHER}"
+        INTERFACE_INCLUDE_DIRECTORIES "${sbsms_INCLUDE_DIR}"
+    )
+  endif()
+endif()