fix: normalise missing names in workspaceFolder responses

[Sam-Sims]

Small PR that addresses the issue described in (#122 (comment))

workspaceFolder names are now normalised before use so that if they are empty, they are populated from the URI file name before use.

e.g

"workspaceFolders": [
  {
    "name": "",
    "uri": "file:///path/to/project/test"
  }
]

becomes

"workspaceFolders": [
  {
    "name": "test",
    "uri": "file:///path/to/project/test"
  }
]

This fixes Zed integration where certain workspace features were disabled as zed sends "" as workspace names.

While doing this I realised it may be better to rework workspaceFolder handling to teat URIs as workspace identifiers instead of names. My Java is a bit rusty though - so haven't attempted that here.

No worries if you'd prefer not to merge this in favour of a more robust fix, but it's working for me with Zed using a locally built langauge server, so will leave it up in case it's useful to anyone else in the meantime.