[Core] Adding hashed containers (currently STL)

[loumalouomega]

📝 Description

This PR introduces unordered_set and unordered_map aliases, in line with the way Kratos defines smart pointers as replacements for STL ones. Historically, this practice originated from our use of Boost smart pointers.

Implementation Details

• The aliases currently use STL implementations.
• In the future, I plan to propose faster alternatives. Initial testing during efforts to modernize data_value_container showed that for scenarios with fewer than 1000 variables, the current brute-force approach outperforms more modern methods.

This lays the groundwork for potential optimizations while maintaining compatibility with existing functionality.

🆕 Changelog

• Adding hashed containers (currently STL)

[roigcarlo]

Mm I don't really see the reason to start changing all the containers now.

Which alternatives are you planning to use? Will be compatible with ranges etc?

[loumalouomega]

Mm I don't really see the reason to start changing all the containers now.

In this PR I am not changing anything. Just adding aliases, I will not full replace all unordered_set and maps at once, if someone wants to replace should do it by himself. For example I have several implementation that may benefice from this.

Which alternatives are you planning to use? Will be compatible with ranges etc?

https://martin.ankerl.com/2022/08/27/hashmap-bench-01/

ankerl in my tests is also the faster solution.