Support for AWS SQS

Support for both reading and writing to/from AWS SQS:

# Writing plaintext
$ plumber write message aws-sqs --queue-name PlumberTestQueue --input-data "hello world"

# Writing protobuf
$ plumber write message aws-sqs --queue-name PlumberTestQueue --input-file ./test-assets/messages/sample-outbound.json --input-type jsonpb --output-type protobuf --protobuf-dir ./test-assets/protos/ --protobuf-root-message Outbound

# Reading plaintext
$ plumber read message aws-sqs --queue-name PlumberTestQueue --auto-delete
INFO[0000] Listening for message(s) ...                  pkg=awssqs/read.go
hello world

# Reading protobuf
$ plumber read message aws-sqs --queue-name PlumberTestQueue --protobuf-dir ./test-assets/protos --protobuf-root-message Outbound --output-type protobuf
INFO[0000] Listening for message(s) ...                  pkg=awssqs/read.go
{
  "replayId": "30ddb850-1aca-4ee5-870c-1bb7b339ee5d",
  "blob": "eyJoZWxsbyI6ImRhbiJ9Cg=="
}

For full info: plumber read message aws-sqs --help and plumber write message aws-sqs --help