optimize CallsiteParameterAdder

[methane]

Summary

CallsiteParameterAdder is slower than logging.Logger.findCaller() because findCaller() doesn't use inspect at all.
This commit doesn't stop using inspect.getframeinfo(), but skips heavy code_context calculation.
This commit changes CallsiteParameterAdder to use frame object directly like findCaller().

Bench:

import structlog
import timeit
import os

null = open(os.devnull, "w", encoding="utf-8")

structlog.configure(
    processors=[
        structlog.processors.CallsiteParameterAdder([
            structlog.processors.CallsiteParameter.FILENAME,
            structlog.processors.CallsiteParameter.LINENO,
            ]),
        structlog.processors.JSONRenderer()
    ],
    logger_factory=structlog.PrintLoggerFactory(null),
    cache_logger_on_first_use=False
)
log = structlog.get_logger()

N = 100_000
x = timeit.timeit(lambda: log.info("hello"), number=N)
print(f"{x*1000_000/N}us")

Result:

before:
18.325596249997034us

getframeinfo(frame, context=0):
12.43612457998097us

use frame directly:
6.971802920015762us

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[hynek]

Great, thank you!

[mdrachuk]

@hynek Can 24.2.0 be released with this one?