Seek better tooling integration by using fuel-toolchain.toml

[nedsalk]

It is possible to define a fuel-toolchain.toml file at the root of a project to use a specific forc and fuel-core version for that project and fuelup will pick it up and use it instead of the currently active global toolchain. Defining this file in our repo would make our internal forc and fuel-core packages obsolete and we could remove them altogether.

[arboleya]

I don't believe we can eliminate the internal packages, as they act as a backbone for development.

But if we can better integrate all the tools, we should.