Add module to handle Glue security configurations

[gsoria]

This PR adds a new module to handle Glue Security Configurations. This module was written by @swhite-oreilly, with the only difference that when checking for the next token apart from checking for nil, it checks for an empty string. That was causing aws-nuke to hang when trying to delete this resource.

Testing

1. Use a test account, and create the glue security configuration

# Create a KMS key
KMS_KEY_ARN=$(aws kms create-key --query 'KeyMetadata.Arn' --output text)
echo "KMS key created: $KMS_KEY_ARN"

# Create a Glue security configuration with the created KMS key ARN
aws glue create-security-configuration \
    --name "testSecurityConfig" \
    --encryption-configuration '{
        "S3Encryption": [
            {
                "S3EncryptionMode": "SSE-KMS",
                "KmsKeyArn": "'"$KMS_KEY_ARN"'"
            }
        ],
        "CloudWatchEncryption": {
            "CloudWatchEncryptionMode": "SSE-KMS",
            "KmsKeyArn": "'"$KMS_KEY_ARN"'"
        },
        "JobBookmarksEncryption": {
            "JobBookmarksEncryptionMode": "CSE-KMS",
            "KmsKeyArn": "'"$KMS_KEY_ARN"'"
        }
    }'
echo "Glue security configuration created"

# Listing security configurations
aws glue get-security-configurations

2. Run aws-nuke against the selected account
3. Check that glue security configurations were correctly deleted aws glue get-security-configurations

[danarbaugh]

I used the script in the supporting PR and witnessed this output after running cleanup following this change:

us-east-1 - GlueSecurityConfiguration - testSecurityConfig - [Name: "testSecurityConfig"] - removed

[swhite-oreilly]

@gsoria sorry I was late on this one. I tested this as well and it worked as expected. What was the line that was causing the hangup from my original try? Just curious.