Add new LHS Brackets: Contains, StartsWith and EndsWith

[IagooCesaar]

Add new LHS bracket options for working with strings:

• Contains: %example%
• StartsWith: example%
• EndsWith: %example

http://localhost:9000/ping?test[contains]=abc&test[startsWith]=def&test[endsWith]=ghi

Based on: https://subscription.packtpub.com/book/web-development/9781800560635/8/ch08lvl1sec40/filtering-api-content