feat: Use serde_repr to (de)serialize Mode and Status enums.

[dlips]

This pull request changes the manual deserialization implementation for the Mode enum to use the serde_repr crate. Due to this change, the behavior on deserialization is modified. Before all unknown values where mapped to Mode::NoFix. Now only the 0 is mapped to Mode::Unknown as defined in the gpsd json protocol. Non-defined values result in a serialization error.

The status field is now also supported as Status enum. Implementation aligns with the new implementation for the Mode enum.

The changes would required increasing the major version.

Initial motiviation for the changes was that the serialize feature was not working due to the fact that there was not Serialize implementation for the Mode enum.

[dlips]

I just realized that the serialization is not fully working as expected because the class field is missing in the generated json.

[bwolf]

Kindly want to ask: what Do you want to achieve with this?

[bwolf]

How should we continue with this? Can you write some tests which fail for your use cases? I think that could be a start. From there we could try to find a route.

[dlips]

Kindly want to ask: what Do you want to achieve with this?

The goal of replacing the numerical values with enums is to make it more typesafe and improve code readability when matching the values of Status and Mode. Alternative would be to define constants for each numerical value.

How should we continue with this? Can you write some tests which fail for your use cases? I think that could be a start. From there we could try to find a route.

I wanted to use the serialization functionality in my tests where I created a fake gpsd server to be used in my integration test. Currently I am using hardcoded json string, which is not optimal for future extensions of test cases.

I will add test cases as you suggested.