Format error in core spec version 0.9.4, context.bap_id and context.bpp_id

**Describe the bug**
The format of context.bap_id and context.bpp_id is set to 'uri'. It is not necessary for the bap_id and bpp_id to be a uri.
`bpp_id:
type: string
format: uri

**Defined here**
https://github.com/beckn/protocol-specifications/blob/core-0.9.4/core/v0/api/core.yaml#L1527

**Expected behavior**
It should be a string type, the bpp_id can be any string