Add option to marshal location text

[charlieegan3]

Fixes #6213

Here is an example of who this change impacts the output of opa parse. Updating the options in opa parse is not required as part of this PR since it's mainly intended for Go API users. However, I felt that it might make sense to include all the location data for now and see what others thought.

opa $ cat file.rego 
package foo

allow := true
opa $ opa version
Version: 0.56.0
Build Commit: 
Build Timestamp: 
Build Hostname: 
Go Version: go1.21.0
Platform: darwin/arm64
WebAssembly: unavailable
opa $ opa parse file.rego -f json --json-include locations
{
  "package": {
    "location": {
      "file": "file.rego",
      "row": 1,
      "col": 1
    },
    "path": [
      {
        "location": {
          "file": "file.rego",
          "row": 1,
          "col": 9
        },
        "type": "var",
        "value": "data"
      },
      {
        "location": {
          "file": "file.rego",
          "row": 1,
          "col": 9
        },
        "type": "string",
        "value": "foo"
      }
    ]
  },
  "rules": [
    {
      "body": [
        {
          "index": 0,
          "location": {
            "file": "file.rego",
            "row": 3,
            "col": 10
          },
          "terms": {
            "location": {
              "file": "file.rego",
              "row": 3,
              "col": 10
            },
            "type": "boolean",
            "value": true
          }
        }
      ],
      "head": {
        "name": "allow",
        "value": {
          "location": {
            "file": "file.rego",
            "row": 3,
            "col": 10
          },
          "type": "boolean",
          "value": true
        },
        "assign": true,
        "ref": [
          {
            "type": "var",
            "value": "allow"
          }
        ],
        "location": {
          "file": "file.rego",
          "row": 3,
          "col": 1
        }
      },
      "location": {
        "file": "file.rego",
        "row": 3,
        "col": 1
      }
    }
  ]
}
opa $ go run main.go parse file.rego -f json --json-include locations
{
  "package": {
    "location": {
      "file": "file.rego",
      "row": 1,
      "col": 1,
      "text": "cGFja2FnZQ=="
    },
    "path": [
      {
        "location": {
          "file": "file.rego",
          "row": 1,
          "col": 9,
          "text": "Zm9v"
        },
        "type": "var",
        "value": "data"
      },
      {
        "location": {
          "file": "file.rego",
          "row": 1,
          "col": 9,
          "text": "Zm9v"
        },
        "type": "string",
        "value": "foo"
      }
    ]
  },
  "rules": [
    {
      "body": [
        {
          "index": 0,
          "location": {
            "file": "file.rego",
            "row": 3,
            "col": 10,
            "text": "dHJ1ZQ=="
          },
          "terms": {
            "location": {
              "file": "file.rego",
              "row": 3,
              "col": 10,
              "text": "dHJ1ZQ=="
            },
            "type": "boolean",
            "value": true
          }
        }
      ],
      "head": {
        "name": "allow",
        "value": {
          "location": {
            "file": "file.rego",
            "row": 3,
            "col": 10,
            "text": "dHJ1ZQ=="
          },
          "type": "boolean",
          "value": true
        },
        "assign": true,
        "ref": [
          {
            "location": {
              "file": "file.rego",
              "row": 3,
              "col": 1,
              "text": "YWxsb3c="
            },
            "type": "var",
            "value": "allow"
          }
        ],
        "location": {
          "file": "file.rego",
          "row": 3,
          "col": 1,
          "text": "YWxsb3cgOj0gdHJ1ZQ=="
        }
      },
      "location": {
        "file": "file.rego",
        "row": 3,
        "col": 1,
        "text": "YWxsb3cgOj0gdHJ1ZQ=="
      }
    }
  ]
}

[srenatus]

✅ ✅ ✅

[charlieegan3]

Thanks Stephan!