More user-friendly error message for pdm add local package.

[Matheus-Ribeiro-ITA]

Is your feature request related to a problem? Please describe.

Hi Frost and PDM team, first awesome package manager!

Could we have a more user-friendly error message for adding a local package to PDM:

Ex:
pdm add ./inexistent_path_with_typo

Returns:

[RequirementError]: Expected package name at the start of dependency specifier
    ./inexistent_path_with_typo
    ^

Describe the solution you'd like

Something like bellow, would be awesome in my opinion

No such file or package found at: file:///${PROJECT_ROOT}/inexistent_path_with_typo

Version

PDM, version 2.5.3