Metadata V16: Implement support for Pallet View Functions (#1981)

* Support Pallet View Functions in Subxt

* fmt

* clippy

* Move a little view function logic to subxt_core

* clippy

* Add back check that prob isnt needed

* avoid vec macro in core

* Add view funciton test and apply various fixes to get it working

* Add test for dynamic view fn call and fix issues

* clippy

* fix test-runtime

* fmt

* remove export

* avoid vec for nostd core

* use const instead of fn for view fn call name

* Update to support latest unstable metadata

* Update metadata stripping tests for new v16 version

core/src/dynamic.rs

@@ -28,6 +28,9 @@ pub use crate::storage::address::dynamic as storage;
 // Execute runtime API function call dynamically.
 pub use crate::runtime_api::payload::dynamic as runtime_api_call;
 
+// Execute View Function API function call dynamically.
+pub use crate::view_functions::payload::dynamic as view_function_call;
+
 /// This is the result of making a dynamic request to a node. From this,
 /// we can return the raw SCALE bytes that we were handed back, or we can
 /// complete the decoding of the bytes into a [`DecodedValue`] type.