This reverts commit 5257f029.

* Building shared C source code as part of the native build for platforms Android, iOS, Linux desktop, MacOS desktop, and Windows desktop.
* Sample code doing a synchronous FFI call.
* Sample code doing a long running synchronous FFI call on a helper isolate.
* Use of `package:ffigen` to generate the bindings.

* Revert "Add libgcrypt as an explicit dependancy on Linux"

This reverts commit bf65b3d03ccdc1dd21c09f34d600d72b0636a784.

* libblkid & liblzma not explicitly required either

This stops them attempting to own a D-Bus name, which may not be possible if the
app is sandboxed (e.g. in a Snap). It's also probably what most developers would
expect is the correct behaviour by default.

* Revert "Add integration_test template to create template (#70240)"

This reverts commit d047d108.

* test

This reverts commit 28db5a0f.

This reverts commit 0b6b3eec.

This reverts commit 70f8fdee.