fix: add cpu_threads to model.yaml

[vansangpfiev]

This pull request introduces a new configuration parameter, cpu_threads, to various parts of the codebase, and refactors the writeKeyValue method to WriteKeyValue for consistency. The most important changes include updates to the ModelConfig structure, YAML handling, and test cases.

New Configuration Parameter cpu_threads:

• engine/cli/command_line_parser.cc: Added cpu_threads to the list of command line options.
• engine/cli/commands/model_upd_cmd.cc: Added handling for the cpu_threads parameter in the UpdateConfig method.
• engine/config/model_config.h: Updated ModelConfig structure to include cpu_threads with appropriate serialization and deserialization logic. [1] [2] [3] [4]
• engine/config/yaml_config.cc: Updated YAML handling to include cpu_threads in ModelConfigFromYaml and UpdateModelConfig methods. [1] [2] [3]

Refactoring writeKeyValue to WriteKeyValue:

• engine/utils/format_utils.h: Renamed writeKeyValue to WriteKeyValue and updated variable names for consistency. [1] [2]
• engine/config/yaml_config.cc: Updated all instances of writeKeyValue to WriteKeyValue.
• engine/test/components/test_format_utils.cc: Updated test cases to use WriteKeyValue.

Test Case Updates:

• engine/test/components/test_yaml_handler.cc: Added test cases for cpu_threads in YAML handling and updated existing tests to include cpu_threads. [1] [2] [3] [4] [5] [6]## Describe Your Changes

Fixes Issues

• Closes #
• Closes #

Self Checklist

• Added relevant comments, esp in complex areas
• Updated docs (for bug fixes / features)
• Created issues for follow-up changes or refactoring needed

[nguyenhoangthuan99]

LGTM!