Roll prepare commands into turbo to allow for parellel

[matthewlilley]

pnpm run prepare to prepare all subgraphs

[OlaStenberg]

@matthewlilley, just to double check, was this issue meant for the new subgraph repo? or you want me to bring in pnpm and turbo here? Haven't we already moved over most subgraphs?

[OlaStenberg]

Some subgraphs are only available on certain networks pnpm run prepare kovan Would you like every subgraph available on kovan to be prepared and ignore the rest?

example

Prepared subgraphs:
miso
furo-stream
..


Skipped:
blocks
legacy