fix(#1114): synchronize shared timings CSV access in benchmarks

[volodya-lombrozo]

Fixes benchmark test failures by introducing a thread-safe shared Tojos instance for concurrent access to timings.csv, preventing NullPointerException when multiple benchmark tests write to the same file simultaneously.

Fixes #1114

[volodya-lombrozo]

@rultor merge

[rultor]

@rultor merge

@volodya-lombrozo OK, I'll try to merge now. You can check the progress of the merge here.

[rultor]

@rultor merge

@volodya-lombrozo Done! FYI, the full log is here (took me 4min).

[0crat]

@volodya-lombrozo Thanks for the contribution! You've earned +12 points for this: +16 as a basis; -4 for too few (20) hits-of-code. Please, keep them coming. Your running score is +378; don't forget to check your Zerocracy account too).