feat: use relative path for model info in data folder

[vansangpfiev]

We store absolute path for yaml path in database. When we transfer the Cortex data folder (models) to another computer or move it between disks/folders, it will break.
We have all model data in the data folder, it makes sense to store relative path in the database.
Note: we have an edge case for import model

Motivation / context: https://discordapp.com/channels/1107178041848909847/1204617960615055401/1290493569156776088

[gabrielle-ong]

@vansangpfiev do we have an issue tracking the edge case for import models?

[vansangpfiev]

@gabrielle-ong Created a ticket for tracking: #1496

[gabrielle-ong]

QA: Mac, Linux, Windows
✅ Successfully transfer models across folders and disks

[gabrielle-ong]

@vansangpfiev clarifying so I can understand this better for docs (no changes needed for v1.0.1)

1. When is the case that users will copy model data folders (is this an edge case or do we want to encourage it?)

2. My understanding is that generally if users copy a model folder in, they will still have to run cortex pull to load the model into cortex.db, is that correct?

Sample test (this may be entirely wrong, cmiiw)

For this screenshot, I copied a new models folder and renamed the old one archived_models
3. Filed to read file: bad file (this is because it is not yet loaded to db?)
4. pull huggingface with model ID TheBloke - failed - why?
5. pull cortexso tinyllama - exists in the model folder, but retriggers download - why?

[vansangpfiev]

@gabrielle-ong This PR is intended for migrating all cortex data folder which includes models engines and cortex.db

[dan-menlo]

@gabrielle-ong I think this PR isn't supposed to cover the "model import" edge case - e.g. copying a model folder in.

@vansangpfiev is just updating Cortex to use relative paths instead of absolute paths. I think we can handle the import scenario in the separate ticket.

@vansangpfiev clarifying so I can understand this better for docs (no changes needed for v1.0.1)

1. When is the case that users will copy model data folders (is this an edge case or do we want to encourage it?)
2. My understanding is that generally if users copy a model folder in, they will still have to run cortex pull to load the model into cortex.db, is that correct?

Sample test (this may be entirely wrong, cmiiw)

For this screenshot, I copied a new models folder and renamed the old one archived_models 3. Filed to read file: bad file (this is because it is not yet loaded to db?) 4. pull huggingface with model ID TheBloke - failed - why? 5. pull cortexso tinyllama - exists in the model folder, but retriggers download - why?