Optimize and improve request module

[lvitals]

Performance Improvements:

• Cached frequently used functions and methods
• Optimized string operations
• Reduced unnecessary table creations

Code Quality:

• Centralized regex patterns as constants
• Improved error handling
• Added safety checks for edge cases
• Reduced code duplication
• Standardized code formatting

Maintainability:

• Better code organization
• More consistent style
• Clearer separation of concerns

[tomasguisasola]

Have you tested the code? I think I found some mistakes:

1. At line 121, the variable _ in your code is a global, but it was a local in the original;
2. At line 158, you could also use a constant for the pattern (just a suggestion);
3. Also at line 158, you should not use %- when using string.find with true as the fourth value, since it turns off the pattern matching facilities (the same occurs at line 160);
4. At lines 159, 161 and 163, the new call input(length) is not the same as the original wsapi_env.input:read(length), since the first argument (wsapi_env.input) is absent: you might correct that!
5. You also make a different metatable, although with the same content, for each :new call