EVM: Bench: remove hardcoded paths

Context

Fixes #6175 (closed)

A lot of path are hardcoded in the benchmark scripts. It's fine for relative path to libs in the benchmark project, but path to external executables and ressources, such as the chunker, the debugger or the kernel became an issue when trying to execute the script outside of a dev environment (eg in a Docker image).

MR also adds a timestamp to the output file name.

Manually testing the MR

node src/kernel_evm/benchmarks/scripts/run_benchmarks.js 

Checklist

• Document the interface of any function added or modified (see the coding guidelines)
• Document any change to the user interface, including configuration parameters (see node configuration)
• Provide automatic testing (see the testing guide).
• For new features and bug fixes, add an item in the appropriate changelog (docs/protocols/alpha.rst for the protocol and the environment, CHANGES.rst at the root of the repository for everything else).
• Select suitable reviewers using the Reviewers field below.
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