Adds 2 new fields to the config file under the mev_params field:
mev_boost_image: <The mev-boost image, default is flashbots/mev-boost>
mev_boost_args: <The args of mev-boost. The default params are
["mev-boost", "--relay-check"]>

The behaviour is such that, `mev-boost-args` overrides all the args of
mev-boost. No extra params are added.

Resolves https://github.com/kurtosis-tech/ethereum-package/issues/289

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Co-authored-by: Barnabas Busa <busa.barnabas@gmail.com>
Co-authored-by: franjoespejo <franjoespejo@gmail.com>
Co-authored-by: Gyanendra Mishra <anomaly.the@gmail.com>
Co-authored-by: Sam Calder-Mason <sam.calder-mason@ethereum.org>
Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: pk910 <github@pk910.de>
Co-authored-by: Parithosh Jayanthi <parithosh.jayanthi@ethereum.org>
Co-authored-by: franjoespejo <franjosepejo@github.com>
Co-authored-by: Anton <anton@northernforest.nl>