Strings searches on MySQL databases are relative slower and CPU intensive

[sherlockwisdom]

https://github.com/smswithoutborders/SMSWithoutBorders-DevAPI/blob/58fb23cc92b1e20da94153abb2ca0228e25fd549/route/authentication.route.js#L27

Refs:

• https://stackoverflow.com/questions/8844080/sql-performance-searching-for-long-strings
• https://stackoverflow.com/questions/8844080/sql-performance-searching-for-long-strings
• https://stackoverflow.com/questions/2346920/sql-select-speed-int-vs-varchar

Enhancements:

• Strings especially emails could be uniquely hashed and stored to reduce overhead