fix: NodeId change for class DataValue

[torarvid]

According to ObjectIds, DataValue = 23, and not 25 as it was before this commit. 25 is DiagnosticInfo, which can also be seen on line 1137 in the uatypes.py file.

(this is my first PR in this repo, and I found it while "just browsing around", so feel free to tell me if I'm completely off here 😉)

Edit: Now using ObjectIds.DataValue instead of 23 to make it more obvious.

[oroulet]

how can such a big bug been around for so long. I am not really getting it. is that attribute not used?

[torarvid]

Btw, I noticed this "just by luck", since I thought it was surprising that the value 25 was used in both DataValue and DiagnosticInfo (they are close together in the file).

But it also got me wondering: why are plain numbers used here? Would it not be easier to spot/prevent bugs like these if the ObjectIds were used? So:

    data_type = NodeId(Int32(ObjectIds.DiagnosticInfo))

instead of

    data_type = NodeId(25)

[oroulet]

historical reason I suppose. Also you probably do not need to cast to Int32. it is done at lower level I suppose.
Crazy that it works with wrong data type for DataValue.... but OK DataValue are probably mostly sent at places where the data type is hardcoded

[torarvid]

Also you probably do not need to cast to Int32

Yeah, I just did it since it made my neovim happier:

[oroulet]

ok then add it. The warning msut come from mypy or the facebook alternative

[torarvid]

@oroulet Oh, did you mean I should change the PR so that instead of using 23 directly, I should just use the ObjectId? Sure, I can do that 👍🏼

(And I think actually it's my Language Server — pyright — that's giving the Int32 error, not mypy)