Support NaN values for timeseries

[ofekshenawa]

This PR implements support for NaN (Not a Number) values in Redis time series commands, enabling developers to insert and retrieve NaN-valued measurements for timestamps where data is unknown, invalid, or unavailable (e.g., broken sensors, unreported values).

[ofekshenawa]

The failures in tests are unrelated to NaN support (They are related to FT.HYBRID and XINFO STREAM)

[ndyakov]

@ofekshenawa the test that I can see failing are related to the NaN changes (actually, the tests you added), since it is not available with the older redis versions in our matrix. We should run those tests only for 8.6+ , maybe you can rebase on top of #3685 to get the new image and matrix for 8.6 ?

[ofekshenawa]

@ndyakov Yes, you're right. I meant the 8.6 test suite that will be implemented in #3685
I'll fix this.