Expose VortexSession in python bindings and switch to CurrentThreadRuntime

[robert3005]

We want to unify the language bindings to have the same behaviour when
interacting with vortex. This pr brings python bindings in line with C and Java
in using CurrentThreadRuntime by default

[codspeed-hq]

Merging this PR will not alter performance

⚠️ Unknown Walltime execution environment detected

Using the Walltime instrument on standard Hosted Runners will lead to inconsistent data.

For the most accurate results, we recommend using CodSpeed Macro Runners: bare-metal machines fine-tuned for performance measurement consistency.

✅ 1210 untouched benchmarks

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_{Comparing rk/pythonchanges (70b7d99) with develop (c663fa9)}