feat(octez): write baker log to file

[huancheng-trili]

Context

Part of JSTZ-244.
JSTZ-244.

Description

Write baker logs to a log file instead of stdout/stderr.

Manually testing the PR

Ran jstzd locally and did not see any baker logs.

[codecov]

Codecov Report

Attention: Patch coverage is 90.90909% with 3 lines in your changes missing coverage. Please review.

Project coverage is 47.23%. Comparing base (60a8fe0) to head (e37df5b).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
crates/octez/src/async/baker.rs	87.50%	0 Missing and 3 partials ⚠️

Files with missing lines	Coverage Δ
crates/jstzd/src/config.rs	97.19% <100.00%> (+0.02%)	⬆️
crates/octez/src/async/baker.rs	93.33% <87.50%> (+4.51%)	⬆️

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