avro

AVRO-2842: PHP Add phpcs and fix all violations against PSR12 (#891)

* AVRO-2842: Add phpcs.

* AVRO-2842: Add PSR4 and code formatting.

* AVRO-2842: Fixed not found callbacks.

* AVRO-2842: Fixed PSR12 violations using phpcbf.

* AVRO-2842: Fixed PSR12 violations.

* Fixed left overs.

* Fixed example

* Added autoloader for non composer usage, updated readme and test bootstrap

* Added license

* Fixed psr issues