Migrate to Active LTS Node.js (14.17.2)

[dractw]

Description

Migrate to stable release of node

Motivation

Bunch of crypto and non-crypto libs were migrated to active lts node api.
Just a little list of them, but truly important part: bufferutil, tiny-secp256k1, even ed25519 wich was updated since 6(!) yrs after latest commit to support Node@14 api.

So in some dapps or lightwallets lisk-sdk have a big chance to became a show-stopper for future support.

Additional Information

or simply remove the engines requirements for node versions, cause at first look lisk-sdk sucessfuly builds with 14 lts.