elrond-wasm 0.26.0

• Major VM API trait refactoring. All API methods can be accessed from a static context. Removed api instance variables from all objects.
• External view contracts
  • Annotating one or more endpoints with #[external_view] triggers the framework to create a second "external view" contract where all these endpoints are placed. This is primarily to reduce the main contract size.
  • General meta crate functionality refactor to allow multiple contract generation.
• ManagedRef type
  • Provided as a more efficient alternative to regular references to managed types
  • Has Copy semantics
  • ManagedVec iterators made safer by the proper use of lifetimes
  • ManagedVec get_mut offers a safe mutable reference, using lifetimes
  • Some initial optimizations in storage mappers
• First version of a message formatter based on ManagedBuffers
  • sc_print! macro
  • sc_panic! macro
• Random number generator wrapper over randomness source from the VM