🐛 [cloud_firestore_odm] json_serializable's field property ignore doesn't work for getters

[bsr203]

Hello,

This pr add support to ignore properties.

below getter

  @JsonKey(ignore: true)
  String get documentId {
    assert(id != null);
    return id!;
  }

still adds these entries (twice)

  XYZQuery whereDocumentId({
 ...
   XYZQuery orderByDocumentId({
...

using as below works.

  @JsonKey(ignore: true)
  String? documentId;

[darshankawar]

/cc @rrousselGit

[rrousselGit]

Looking at this issue, do we even want to support getters?

Since getters are not available in the Firestore DB, I don't see how doing something like whereMyGetter(..) would ever be useful.

So rather than applying JsonKey(ignore: true) to getters, wouldn't it make more sense to ignore all getters entirely?
They aren't present in the JSON after-all.