Refactor the locationId constant for the subdirectory-based
deployments support.
Exclude the MFE's `PUBLIC_PATH` from the constant.
The `window.location.pathname` example:
```
<PUBLIC_PATH>block-v1:oragrading+oragrading+oragrading+type@openassessment+block@ee217e897a954c1faa3b29317da0f2e7
```
Where the `PUBLIC_PATH` could be:
- `'/'` - for subdomain-based deployments (default)
- `'/mfe-specifix-public-path/'` - for subdirectory-based deployments
cc349faeb2