Search available phone numbers by the first/last part of the number

[OSvirhun]

Issue Summary

Currently, there are static methods Read and ReadAsync of LocalResource class to search for available phone numbers. They allow only the contains property for phone number searching. At the same time, twilio.com/console/phone-numbers/api/v1/available-phone-numbers/numbers supports parameter searchFilter which is responsible for searching direction.

Proposition

1. Adjust supporting of phone numbers searching with searchFilter options like StartsWith, Anywhere, and EndsWith

Technical details:

• twilio-csharp version: 7.4.0