cli: Include file path in WGSL parse error

[rhysd]

Adding the file path to WGSL parse error output from naga would be better since a tool which uses the output can easily parse the file path from it

Before:

error: expected global item ('struct', 'let', 'var', 'type', ';', 'fn') or the end of the file, found '['
  ┌─ wgsl:5:1
  │
5 │ [[group(1), binding(0)]]
  │ ^ expected global item ('struct', 'let', 'var', 'type', ';', 'fn') or the end of the file

Could not parse WGSL

After:

error: expected global item ('struct', 'let', 'var', 'type', ';', 'fn') or the end of the file, found '['
  ┌─ /path/to/test.wgsl:5:1
  │
5 │ [[group(1), binding(0)]]
  │ ^ expected global item ('struct', 'let', 'var', 'type', ';', 'fn') or the end of the file

Could not parse WGSL