Support for selectable hashmap implementation in the combiner_perf

[pzuev]

Also:

• change the timing method (use the thread CPU time)
• fix bar colors in the result chart, remove the "bytes per key" column from the formatted table

Changelog category

• Not for changelog (changelog entry is not required)

[github-actions]

⚪ 2025-05-05 10:59:20 UTC Pre-commit check linux-x86_64-release-asan for 66cff16 has started.
⚪ 2025-05-05 10:59:40 UTC Artifacts will be uploaded here
⚪ 2025-05-05 11:02:39 UTC ya make is running...
🟢 2025-05-05 11:03:40 UTC Tests successful.

Test history | Ya make output | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
0	0	0	0	0	0

🟢 2025-05-05 11:03:46 UTC Build successful.

[github-actions]

🟢 2025-05-05 11:02:08 UTC The validation of the Pull Request description is successful.

[github-actions]

⚪ 2025-05-05 11:39:02 UTC Pre-commit check linux-x86_64-relwithdebinfo for 66cff16 has started.
⚪ 2025-05-05 11:39:25 UTC Artifacts will be uploaded here
⚪ 2025-05-05 11:42:44 UTC ya make is running...
🟢 2025-05-05 11:43:59 UTC Tests successful.

Test history | Ya make output | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
0	0	0	0	0	0

🟢 2025-05-05 11:44:04 UTC Build successful.