[refactoring] Group all the CBOR util functions in cbor_util

This cl only moves all the CBOR utility functions in one place.
Some return error types are adjusted to adapt the change. There
should be no behavior change.

Bug: 310931749
Test: atest rialto_test
Change-Id: Ie3db9c93b1355d25d7d796818e19e554560e1f23
diff --git a/service_vm/comm/Android.bp b/service_vm/comm/Android.bp
index bdfc099..bf923a4 100644
--- a/service_vm/comm/Android.bp
+++ b/service_vm/comm/Android.bp
@@ -23,6 +23,7 @@
     rustlibs: [
         "libbssl_avf_error_nostd",
         "libciborium_nostd",
+        "libcbor_util_nostd",
         "libcoset_nostd",
         "libder_nostd",
         "liblog_rust_nostd",
@@ -36,6 +37,7 @@
     rustlibs: [
         "libbssl_avf_error",
         "libciborium",
+        "libcbor_util",
         "libcoset",
         "liblog_rust",
         "libserde",