Switch to use [central package management](https://learn.microsoft.com/en-us/nuget/consume-packages/central-package-management) by adding a `Directory.Packages.props` and add all package version information there.

Simplify dependencies as the inheritdoc functionality works without external libraries in modern IDEs

Update the benchmark project to use .NET9.

According to [JetBrains](https://github.com/JetBrains/resharper-rider-samples/blob/master/.gitignore) some files in the `.idea` directory should not be excluded.

Remove support for .NET 7 as Microsoft support [ended on May 14, 2024](https://dotnet.microsoft.com/en-us/platform/support/policy/dotnet-core). The supported frameworks still are:
- (net462)
- netstandard2.0
- netstandard2.1
- net6.0
- net8.0
- net9.0

Fix build warnings in test projects.

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

…to v5.4.4 (#1206)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

In order to simplify extensibility, move the filesystem interfaces to a separate package ["Testably.Abstractions.FileSystem.Interface"](https://www.nuget.org/packages/Testably.Abstractions.FileSystem.Interface), that will keep its version in sync with the .NET versioning scheme (starting with v9.0.0).

Preparation for migrating to xunit, as the runner there also requires minimum framework version 4.7.2