[#242] Better error message when `tezos-client` program is missing

Description

Changes the error that is thrown when tezos-client program in missing to be more helpful. Main changes are

1. Wrap readProcessWithExitCode in helper function that catches the exception and prints a helpful error.
2. Add ansi-terminal package to color the printed error so that it will be noticed easily.

Related issue(s)

Resolves #242 (closed)

✅ Checklist for your Merge Request

Related changes (conditional)

• Tests (see short guidelines)

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