Change report modal to include category selection in web UI (#17565)

* Change report modal to include category selection in web UI

* Various fixes and improvements

- Change thank you text to be different based on category
- Change starting headline to be different for account and status reports
- Change toggle components to have a checkmark when checked
- Fix report dialog being cut off on small screens
- Fix thank you screen offering mute or block if already muted or blocked
- Refactor toggle components in report dialog into one component

* Change wording on final screen

* Change checkboxes to be square when multiple options are possible

app/javascript/mastodon/actions/rules.js

@@ -0,0 +1,27 @@
+import api from '../api';
+
+export const RULES_FETCH_REQUEST = 'RULES_FETCH_REQUEST';
+export const RULES_FETCH_SUCCESS = 'RULES_FETCH_SUCCESS';
+export const RULES_FETCH_FAIL    = 'RULES_FETCH_FAIL';
+
+export const fetchRules = () => (dispatch, getState) => {
+  dispatch(fetchRulesRequest());
+
+  api(getState)
+    .get('/api/v1/instance').then(({ data }) => dispatch(fetchRulesSuccess(data.rules)))
+    .catch(err => dispatch(fetchRulesFail(err)));
+};
+
+const fetchRulesRequest = () => ({
+  type: RULES_FETCH_REQUEST,
+});
+
+const fetchRulesSuccess = rules => ({
+  type: RULES_FETCH_SUCCESS,
+  rules,
+});
+
+const fetchRulesFail = error => ({
+  type: RULES_FETCH_FAIL,
+  error,
+});