Support legacy import

[vedran-kasalica]

The feature that allows the use of legacy metadata files (tsdb). This will be important when importing PPP data from Snellius.

In addition, the formatting of the notebook was improved (lines were not fully visible in the online browser, see Issue 15).

[kretep]

Could you clean up the exceptions in the processing_example.ipynb output?

[vedran-kasalica]

processing_example

Sure, I will fix that.

[vedran-kasalica]

@kretep I fixed the notebook outputs, however, due to circular import issues, I had to refactor the code. I did not change the content of the methods, I just re-organised them. The main change is that I split io module, which was quite large, not clear and was causing the mentioned issue into:

• file_utils,
• write_binary,
• read_binary,
• write_tsdf,
• read_tsdf

We ended up now with many modules so we might want to group them into packages, or maybe merge some, but I could not find a more elegant alternative to solve the circular imports straight away.

Another reason for the circular imports issue was the repeated import of TSDFmetadata class, often used just for typing. I started using forward reference to mitigate that in the future.