feat: add backend url path completion

[McPatate]

This PR:

• adds auto-completion of the path depending on the backend to avoid
• adds a feature flag to disable this functionality

Closes #80

[github-actions[bot]]

Repository name	Source type	Average hole completion time (s)	Pass percentage
smol-rs/async-executor	github	5.449	0.00%
jaemk/cached	github	11.402	0.00%
tkaitchuck/constrandom	github	16.796	0.00%
tiangolo/fastapi	github	29.336	29.95%
null	null	null	null%
huggingface/huggingface_hub	github	25.985	40.00%
gcanti/io-ts	github	25.029	60.00%
lancedb/lancedb	github	111.765	0.00%
mmaitre314/picklescan	github	17.170	0.00%
simple	local	2.786	0.00%
encode/starlette	github	12.353	0.00%
colinhacks/zod	github	9.467	0.00%

Note: The "hole completion time" represents the full process of:

• copying files from the setup cache directory
• replacing the code from the file with a completion from the model
• building the project
• running the tests