tests(parsers, ESTADISTICO_UT): add snapshot test for historical prod

[consideRatio]

Issue

Ping @PaulRoms and @VIKTORVAV99 - this follows up on #7739 (comment).

I'm sorry for jumping in like this without asking first -- I initially thought @PaulRoms was a repo maintainer and that I could offload to free up time to be used more impactfully.

Description

Adds a snapshot test for fetch_production with a passed target_datetime, which since #7739 works.

About how this PR was created

I modified the fetch_production function to dump files with the response data, like this:

    # ...
    initial_resp = session.get(DAILY_OPERATION_URL)
    with open("get_historical.html", "w") as f:
        f.write(initial_resp.text)

    # ...
    data_resp = session.post(DAILY_OPERATION_URL, data=post_data)
    with open("post_historical.html", "w") as f:
        f.write(data_resp.text)

Then I just moved these files to the mocks folder and copy-pasted-tweaked a snapshot test.

Double check

• I have tested my parser changes locally with poetry run test_parser "zone_key"
• I have run pnpx prettier@2 --write . and poetry run format in the top level directory to format my changes.

[VIKTORVAV99]

WoHoo!

Nice work!

Thanks!

[PaulRoms]

Thank you @consideRatio !