GORA-478 Address Sonar issues within gora-accumulo Encoder classes

[lewismc]

This issue addresses https://issues.apache.org/jira/browse/GORA-478
It

• uses the @OverRide notation where appropriate
• uses try-with-resources notation to greatly reduce the amount of incorrect exception handling, steam closing and encoder closing, this has the knock on issue of better Encoder APi design where Exceptions are included and enforced as part of the Encoder interface
• implements very trivial safety improvements such as moving array declarations from variables to types, and uppercasing 'l' to 'L' for long values.

[renato2099]

👍 Thanks @lewismc !