(core) move client code to core

Summary:
This moves all client code to core, and makes minimal fix-ups to
get grist and grist-core to compile correctly.  The client works
in core, but I'm leaving clean-up around the build and bundles to
follow-up.

Test Plan: existing tests pass; server-dev bundle looks sane

Reviewers: dsagal

Reviewed By: dsagal

Differential Revision: https://phab.getgrist.com/D2627

app/client/models/UserPrefs.ts

@@ -0,0 +1,41 @@
+import {localStorageObs} from 'app/client/lib/localStorageObs';
+import {AppModel} from 'app/client/models/AppModel';
+import {UserOrgPrefs} from 'app/common/Prefs';
+import {Computed, Observable} from 'grainjs';
+
+/**
+ * Creates an observable that returns UserOrgPrefs, and which stores them when set.
+ *
+ * For anon user, the prefs live in localStorage. Note that the observable isn't actually watching
+ * for changes on the server, it will only change when set.
+ */
+export function getUserOrgPrefsObs(appModel: AppModel): Observable<UserOrgPrefs> {
+  const savedPrefs = appModel.currentValidUser ? appModel.currentOrg?.userOrgPrefs : undefined;
+  if (savedPrefs) {
+    const prefsObs = Observable.create<UserOrgPrefs>(null, savedPrefs);
+    return Computed.create(null, (use) => use(prefsObs))
+      .onWrite(userOrgPrefs => {
+        prefsObs.set(userOrgPrefs);
+        return appModel.api.updateOrg('current', {userOrgPrefs});
+      });
+  } else {
+    const userId = appModel.currentUser?.id || 0;
+    const jsonPrefsObs = localStorageObs(`userOrgPrefs:u=${userId}`);
+    return Computed.create(null, jsonPrefsObs, (use, p) => (p && JSON.parse(p) || {}) as UserOrgPrefs)
+      .onWrite(userOrgPrefs => {
+        jsonPrefsObs.set(JSON.stringify(userOrgPrefs));
+      });
+  }
+}
+
+/**
+ * Creates an observable that returns a particular preference value from UserOrgPrefs, and which
+ * stores it when set.
+ */
+export function getUserOrgPrefObs<Name extends keyof UserOrgPrefs>(
+  appModel: AppModel, prefName: Name
+): Observable<UserOrgPrefs[Name]> {
+  const prefsObs = getUserOrgPrefsObs(appModel);
+  return Computed.create(null, (use) => use(prefsObs)[prefName])
+  .onWrite(value => prefsObs.set({...prefsObs.get(), [prefName]: value}));
+}