Fix Configuration Parser For Size Units

[LucioDonda]

Wazuh version	Component	Install type	Install method	Platform
5.0.0	Configration Parser	Agent	Sources	-

Description

After the implementation #385 it was forced to implement a workaround on the configuration parser in order to correctly handle the size units.

LINK

        // This is a workaround for parsing size units
        if (std::string_view(key) == "batch_size")
        {
            should_parse_size = true;
        }

Initially it was implemented using size_t as the type but that was opening a possible conflict with using size_t as his own (e.g. while parsing threads).
Later another option was creating a custom type but that need to shared the header where it's defined in every module that uses it.
Another option was getting the output type and the parsing type from arguments of the template.

• Design a solution that solves the previous issues.
• Apply changes.
• Correct and / or add any Unit Test needed.