Convert boolean and numeric values to strings for value comparison

[ewbankkit]

Supersedes jen20#12.

Relates hashicorp/terraform-provider-aws#21225.
Relates hashicorp/terraform-provider-aws#19245
Relates hashicorp/terraform-provider-aws#21968

The AWS IAM policy language states that Quotation marks are optional for numeric and Boolean values, so for example

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Sid": "statement1",
      "Effect": "Allow",
      "Action": [
        "s3:PutObject"
      ],
      "Resource": [
        "arn:aws:s3:::examplebucket/*"
      ],
      "Condition": {
        "Bool": {
          "aws:MultiFactorAuthPresent": "true"
        }
      }
    }
  ]
 }

and

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Sid": "statement1",
      "Effect": "Allow",
      "Action": [
        "s3:PutObject"
      ],
      "Resource": [
        "arn:aws:s3:::examplebucket/*"
      ],
      "Condition": {
        "Bool": {
          "aws:MultiFactorAuthPresent": true
        }
      }
    }
  ]
 }

should evaluate as equivalent.

% go test -v ./
=== RUN   TestParseAwsArnString
--- PASS: TestParseAwsArnString (0.00s)
=== RUN   TestPolicyEquivalence
--- PASS: TestPolicyEquivalence (0.00s)
PASS
ok  	github.com/jen20/awspolicyequivalence	0.616s

[YakDriver]

Looks fantastic! 🎉