Prepared statements not working with Dolt table functions

[tbantle22]

Query:

q: "SELECT * FROM dolt_diff_stat($1, $2)"
p: ["HEAD", "WORKING"],

Error:
error: unsupported syntax: :v1 (errno 1105) (sqlstate HY000)

Query with type cast:

q: "SELECT * FROM dolt_diff_stat($1::text, $2::text)"
p: ["HEAD", "WORKING"],

Error:

error: runtime error: invalid memory address or nil pointer dereference
    at Parser.parseErrorMessage (/Users/taylor/go/src/github.com/dolthub/doltgresql/testing/postgres-client-tests/node/node_modules/pg-protocol/dist/parser.js:283:98)
    at Parser.handlePacket (/Users/taylor/go/src/github.com/dolthub/doltgresql/testing/postgres-client-tests/node/node_modules/pg-protocol/dist/parser.js:122:29)
    at Parser.parse (/Users/taylor/go/src/github.com/dolthub/doltgresql/testing/postgres-client-tests/node/node_modules/pg-protocol/dist/parser.js:35:38)
    at Socket.<anonymous> (/Users/taylor/go/src/github.com/dolthub/doltgresql/testing/postgres-client-tests/node/node_modules/pg-protocol/dist/index.js:11:42)
    at Socket.emit (node:events:520:28)
    at addChunk (node:internal/streams/readable:559:12)
    at readableAddChunkPushByteMode (node:internal/streams/readable:510:3)
    at Readable.push (node:internal/streams/readable:390:5)
    at TCP.onStreamRead (node:internal/stream_base_commons:191:23) {
  length: 85,
  severity: 'ERROR',
  code: 'XX000',
  detail: undefined,
  hint: undefined,
  position: undefined,
  internalPosition: undefined,
  internalQuery: undefined,
  where: undefined,
  schema: undefined,
  table: undefined,
  column: undefined,
  dataType: undefined,
  constraint: undefined,
  file: undefined,
  line: undefined,
  routine: undefined
}

There are a bunch of workbench tests here that could be updated to use prepared statements