[ZEPPELIN-6427] Convert interpreter setting form to typed reactive forms

### What is this PR for?

Numeric interpreter properties edited in the Angular UI are sent as JSON numbers, which Gson deserializes as `Double` (`60000` → `"60000.0"`), breaking `Long`/`Integer` parsing in interpreters such as JDBC (ZEPPELIN-6395). The server-side workaround from ZEPPELIN-6131 only covers the update path, not create.

This PR fixes it on the client by converting `InterpreterItemComponent` from `UntypedFormBuilder` to typed reactive forms:

- Non-checkbox values are sent as strings (like the classic UI); checkbox values stay real booleans, and `"true"`/`"false"` strings from corrupted data are normalized back on save.
- New request DTOs mirror the fields `InterpreterOption.java` actually reads; the UI-only `session`/`process` fields (dead since ZEPPELIN-1210) are no longer sent.
- Fixes wrong `Properties.value`/`type` interface types; response option fields that Gson omits when null are now optional.

Alternative to #5147, which stringifies checkbox booleans too — persisting `"false"` makes an unchecked checkbox render as checked on reload. Credit to <at>kevinjmh for the original diagnosis.

### What type of PR is it?
Improvement

### What is the Jira issue?
https://issues.apache.org/jira/browse/ZEPPELIN-6427 (fixes ZEPPELIN-6395)

### How should this be tested?

No unit test infra exists in `zeppelin-web-angular` (Playwright e2e only), so verified by `ng build` (strict, 0 errors), lint/prettier, and manually: numeric property saves as `"60000"` in `interpreter.json` (create and update), JDBC paragraph runs without `NumberFormatException`, unchecked checkbox stays unchecked after reload, and a regression pass over create/edit/cancel, property and dependency CRUD, and interpreter binding mode options.

### Screenshots (if appropriate)
N/A

### Questions:
* Does the license files need to update? No
* Is there breaking changes for older versions? No
* Does this needs documentation? No


Closes #5265 from tbonelee/ZEPPELIN-6427-typed-interpreter-forms.

Signed-off-by: ChanHo Lee <chanholee@apache.org>