Fix edit prediction disablement with "disable_ai": true setting (#35513)

Even after #35327 edit predictions were still being queried and shown
after setting `"disable_ai": true`

Also moves `DisableAiSettings` to the `project` crate so that it gets
included in tests via existing use of `Project::init_settings(cx)`.

Release Notes:

- Fixed `"disable_ai": true` setting disabling edit predictions.

crates/inline_completion_button/src/inline_completion_button.rs

@@ -1,5 +1,5 @@
 use anyhow::Result;
-use client::{DisableAiSettings, UserStore, zed_urls};
+use client::{UserStore, zed_urls};
 use cloud_llm_client::UsageLimit;
 use copilot::{Copilot, Status};
 use editor::{
@@ -19,6 +19,7 @@ use language::{
     EditPredictionsMode, File, Language,
     language_settings::{self, AllLanguageSettings, EditPredictionProvider, all_language_settings},
 };
+use project::DisableAiSettings;
 use regex::Regex;
 use settings::{Settings, SettingsStore, update_settings_file};
 use std::{