Schema path is not correctly escaped

[jirutka]

Describe the bug

The schema path in the path argument of the mutation function is not escaped.

To Reproduce

traverse({
  type: 'object',
  properties: {
    '.foo': {
      type: 'string'
    },
    '.': {
      type: 'object',
      properties: {
        'x': {
          type: 'number'
        }
      }
    },
    '[foo]': {
      type: 'string',
    },
  },
}, (schema, _isCycle, path) => {
  console.log(path)
  return schema
})

"$.properties..foo"
"$.properties...properties.x"
"$.properties.."
"$.properties.[foo]"
"$"

Expected behavior

"$.properties['.foo']"
"$.properties['.'].properties.x"
"$.properties['.']"
"$.properties['[foo]']"
"$"

…or use JSON Pointer instead of JSON Path:

"/properties/.foo"
"/properties/./properties/x"
"/properties/."
"/properties/[foo]"

…or just return an array of the path segments:

["properties", ".foo"]
["properties", ".", "properties", "x"]
["properties", "."]
["properties", "[foo]"]

JSON Path is not a good fit for this because it`s a query language, not an identifier, so it’s quite complex.

JSON Pointer is simpler and easier to work with. It has only two special characters: / which is escaped as ~1, and ~ which is escaped as ~0.