Dmitrii Novikov

First linked issue seems misprinted for the PR

@SabaunT, seems that you forget to specify wasm-instrument crate source

> relates to #880 I don't actually think so. It's more about outdated paused programs

Defer messages sending is 100% must-have-feature, but I'm not sure that other 3 methods are necessary. It also becomes hard to provide such api for the functions: user space should...

It's too hard to implement separately, but will be done in some approach if wasm binaries become able to cut in parts

> since `gcore` contains custom interfaces for host functions, we need to provide a new interface to parse the error replies also? > > otherwise, for just parsing the error...

> What's the progress? @ukint-vs Here may not be any progress at all. It's more about just to consider how much we should pay. No benchmarks *for memory usage* may...

Also need to add license header for each file

Part of #196

I have already wrote a lot of doc for it, but for [wiki article](https://wiki.gear-tech.io/developing-contracts/testing) only. They should be adapted and updated, added for whole crate afterward.