Add price based search filter

[mahdirezaei-dev]

I created a filter to search for products based on price by 3 methods:

• priceBetween
• priceGreaterThan
• priceLessThan

After that, I wrote some tests to check the performance of the methods

[mahdirezaei-dev]

Is there any problem that you did not accept ?🤔 @fulopattila122

[fulopattila122]

Thanks a lot! Will be released along with v4.1

[fulopattila122]

I've amended the methods a little bit to avoid confusion:

• priceGreaterThan uses the > operator instead of >=
• priceLessThan uses the < operator instead of <=
• added the priceGreaterThanOrEqualTo method: uses the >= comparison
• added the priceLessThanOrEqualTo method uses the <= comparison

This complies with PHP standard operator naming: https://www.php.net/manual/en/language.operators.comparison.php