Improve search of SRTP.

Update CMakeLists.txt so that ms2 can be built with bzrtp in the tree of linphone-sdk.

Rename ENABLE_NON_FREE_CODECS option to ENABLE_NON_FREE_FEATURES because this option is now also used for cryptography purposes.

Fix build on Windows.

Fix build for mac arm64.

Remove now useless LINPHONE_BUILDER_GROUP_EXTERNAL_SOURCE_PATH_BUILDERS code.

Find Android specific dependencies.

Do not build tester executable for Android.

Small CMake fixes when cross-compiling.

Fix for build outside of linphone-sdk.

Rename CMake targets for uniform naming.