Use path prefix as default prefix when loading models

[NRHelmi]

This PR adds the ability to the cli to use models paths as prefix by default like explained below:

• Default behavior

rai load-models DB_NAME --engine ENGINE_NAME path1/to/model1.rel path2/to/model2.rel

Models will be loaded under path1/to/model1 and path2/to/model2 prefixes.

• Override default behavior by specifying --prefix

rai load-models DB_NAME --engine ENGINE_NAME path1/to/model1.rel path2/to/model2.rel --prefix ""

Models will be loaded under model1 and model2

[larf311]

Need to update the CHANGELOG since this is a breaking change. Or I guess maybe we only need to do that on the next release.

[bradlo]

did this get merged? i dont see the branch in the list of remote branches?

[NRHelmi]

did this get merged? i dont see the branch in the list of remote branches?

@bradlo this work is not yet merged, the branch is still there
https://github.com/RelationalAI/rai-cli/tree/hnr-hierarchical-structure-models

[bradlo]

what exactly is the semantic for use of paths in file names? aside from the prefix arg? eg: i assume we canonicalize paths in some way? what does ../foo/../bar/baz/model.rel do? what if its a path from home, eg: ~/bar/baz/model? and what about a fully qualified path? the original idea was to use the basename, and prepend any prefix provided by the prefix arg. simple and unambiguous. what use case does this not handle?