Feature: Expand error codes (#545)

* WC-4057: Added more modbus error codes to the table.

* index.js: Tweak undefined error code 9

To be consistent with the similarly undefined error code 0.

* index.js: Drop inline index number comments on errors table.

```
     Error: Code did not pass lint rulesindex.js: line 38, col 5, Error - Expected space or tab after '/*' in comment. (spaced-comment)
index.js: line 39, col 5, Error - Expected space or tab after '/*' in comment. (spaced-comment)
index.js: line 40, col 5, Error - Expected space or tab after '/*' in comment. (spaced-comment)
index.js: line 41, col 5, Error - Expected space or tab after '/*' in comment. (spaced-comment)
index.js: line 42, col 5, Error - Expected space or tab after '/*' in comment. (spaced-comment)
index.js: line 43, col 5, Error - Expected space or tab after '/*' in comment. (spaced-comment)
index.js: line 44, col 5, Error - Expected space or tab after '/*' in comment. (spaced-comment)
index.js: line 45, col 5, Error - Expected space or tab after '/*' in comment. (spaced-comment)
index.js: line 46, col 5, Error - Expected space or tab after '/*' in comment. (spaced-comment)
index.js: line 47, col 5, Error - Expected space or tab after '/*' in comment. (spaced-comment)
index.js: line 48, col 5, Error - Expected space or tab after '/*' in comment. (spaced-comment)
index.js: line 49, col 5, Error - Expected space or tab after '/*' in comment. (spaced-comment)

12 problems
      at Context.<anonymous> (node_modules/mocha-eslint/index.js:38:15)
      at processImmediate (node:internal/timers:466:21)
```

Sorry @SamuelToh, those comments have got to go:

---------

Co-authored-by: SamuelToh <[email protected]>

index.js

@@ -41,7 +41,12 @@ const modbusErrorMessages = [
     "Illegal data value (value cannot be written to this register)",
     "Slave device failure (device reports internal error)",
     "Acknowledge (requested data will be available later)",
-    "Slave device busy (retry request again later)"
+    "Slave device busy (retry request again later)",
+    "Negative acknowledge (slave device cannot perform programming functions)",
+    "Memory parity error (slave device detected a parity error in memory)",
+    "Unknown error",
+    "Gateway path unavailable (misconfigured gateway)",
+    "Gateway target device failed to respond (retry request again later)"
 ];
 
 const PortNotOpenError = function() {