feat: filter modules, classes, functions, and parameters

[lars-reimann]

Closes #7.

Summary of Changes

• Filter box in the menu bar.
• Expected input has the form <scope>:<filterString>, where scope is one of module, class, function, or parameter and filterString is an arbitrary string. Each scope must occur at most once.
• The filterString must occur anywhere in the name of the declaration for it to be matched. This means module:neighbors would match sklearn.neighbors._kde, for example.
• Search is case-insensitive.
• When the class filter is active, all top-level functions are removed.
• When any filter is active, nodes in the tree view without children are removed.

Screenshots

Testing instructions

• Try the following queries and vary them:
  • module:neighbors
  • class:transformer
  • function:fit
  • parameter:y
• Check that the original view is reinstantiated when the filters are removed

[paul0314]

Nach der Eingabe "parameter:WhateverTest" werden nur vereinzelt Module entfernt und weiterhin Parameter angezeigt, die nicht den String "WhateverTest" enthalten.

[paul0314]

LGTM.
Frage mich nur, ob es beabsichtigt ist, dass die Datei empty.json zum Projekt hinzugefügt wird? Falls ja merge es gerne rein.

[lars-reimann]

Habe ich erstmal mir reingepackt, damit wir eine weitere Datei zum Testen haben, insbesondere für diesen Edge-Case.