Improve validate cmd parameters

**Description**
Add support for configs based on the number of available CPUs, like '50% of all available CPUs'. Based on the comment: https://github.com/hiero-ledger/hiero-consensus-node/pull/22215#discussion_r2663036430

**Dependencies**
https://github.com/hiero-ledger/hiero-consensus-node/pull/22215 is merged

Start with the command-parameter validation entry point and review merged pull request #22215, especially the referenced discussion. Implement support for configuration values expressed as a percentage of available CPUs, then verify that validation accepts the new form and preserves existing parameter behavior.

Written by the indexing model from the issue text.