Sync fvm-wasm-instrument with upstream

[Stebalien]

Upstream (https://github.com/paritytech/wasm-instrument) has seen recent development. While we've pretty much completely forked off, we should investigate the latest changes (looks like more accurate charging for functions) and consider backporting their changes.

[Stebalien]

cc @magik6k in case you get some spare cycles.

[maciejwitowski]

@Stebalien do we need this for M2.1?

[Stebalien]

No.