elrond-wasm 0.31.0, elrond-codec 0.11.0, mandos 0.13.0

• Improved formatter. Strings can be formatted similarly to the standard Rust ones, but without allocator, using managed buffers. Macros require!, sc_panic!, sc_format!, sc_print! use it.
• Removed build flag ei-1-1, following mainnet updated and new VM endpoints being available. Among others, managed sha256 and keccak256 APIs can be used freely.
• CodecFrom and CodecInto traits to define equivalent encodings and conversions via codec.
• Generated smart contract proxies use the CodecFrom/CodecInto traits to accept a wider range of types.
• Mandos Rust testing framework v2, which uses contract proxies for composing calls and is capable of building and exporting mandos scenarios.
• Managed type handle management system in the contract, to reduce the number of API calls to the VM. General VM API refactor.
• Eliminated #[var_args] annotation. The framework can now distinguish between single-values and multi-values solely based on type.
• Contract cleans up return data after performing synchronous calls. Getting return data by range is no longer needed and the respective methods have been removed.
• Fixed behavior of blockchain API get_esdt_token_data.
• Git tag/commit info in ABI (fixed & reintroduced).