Add performance testing

[mciszczon]

This PR introduces a basic set of performance tests (achieved with pytest-benchmark), as well as a Github Actions integration to make it easier to work with the performance testing, as well as control any unwanted degradation of the performance.

Implemented changes

• Added pre-commit hook configuration, to automatically run black on commit.
• Installed pytest-benchmark library to handle benchmarking.
• Added tests/performance/* directory, which contains all the performance tests, related dataclasses and fixtures.
• Configure dpytest to run performance tests and ensure valid output.
• Added benchmark-action/github-action-benchmark@v1 Github Action that runs performance tests, adds comments with the results and can even fail a CI run if the performance has significantly worsened.
• A new performance page will be generated, with history of commits to show how performance changed over time. It will be available at https://konradhalas.github.io/dacite/performance/X.Y, where X.Y is the related Python version from Github Actions matrix (e.g. 3.11).

Suggested actions

Before accepting and merging this PR, it is recommended to:

1. Create an empty gh-pages branch in konradhalas/dacite repo.
2. A personal Github Token should be generated, and added to the repository Secrets with the GITHUB_TOKEN key. The token must have the following permissions:
   • Access to konradhalas/dacite repo.
   • Actions: Read and write access.
   • Pull requests: Read and write access.
   • Contents: Read and write access