docker: Add rust-sdk memcheck target.

docker: Separate and tweak cargo cache paths.

ci: Improve memcheck job targets.

cargo: Add missing debug syms to bench profile.

docker: Optimize layer copying.

Signed-off-by: Jason Volk <jason@zemos.net>

Cargo.toml

@@ -704,8 +704,8 @@ inherits = "release-native.build-override"
 #]
 
 [profile.bench]
-debug = false
-strip = false
+debug = "limited"
+strip = "none"
 #rustflags = [
 #	"-Cremark=all",
 #	'-Ztime-passes',