Align Forest send command behavior with the one from Lotus

[elmattic]

Issue summary

Lotus send command allows to specify the token amount in either FIL or attoFIL denominations.
That's not the case for Forest send command where it expects attoFIL.

• Add support of similar behaviour.
• Add tests covering the different denominations.
• Update the documentation accordingly.
• Make sure sendFIL still works in the JavaScript console

Other information and links

https://github.com/filecoin-project/lotus/blob/master/cli/send.go#L96
https://github.com/filecoin-project/lotus/blob/master/chain/types/fil.go#L86

[LesnyRumcajs]

I'd also add a strong emphasis on updating the documentation. The user sending 1e18 FIL by just following the docs may get confused. https://github.com/ChainSafe/forest/blob/main/documentation/src/docker.md

[elmattic]

I'd also add a strong emphasis on updating the documentation. The user sending 1e18 FIL by just following the docs may get confused. https://github.com/ChainSafe/forest/blob/main/documentation/src/docker.md

Very good point.