message_edit: Show modal if user cannot resolve topics.

We show a modal if user is not allowed to resolve or unresolve
topics due to time limit. The modal just contains the text
mentioning user cannot resolve topic without stating the
count of messages that are within the time limit as we do
not recommend partial resolving of topics.

This commit does not include any changes for resolving or
unresolving topic using "Move topic" or "Move message" modals,
as we will still consider them as simple topic move and show
the same modal that is shown in general for moving message.

web/src/timerender.ts

@@ -455,3 +455,25 @@ export function get_full_datetime(time: Date): string {
 
     return $t({defaultMessage: "{date} at {time}"}, {date: date_string, time: time_string});
 }
+
+type TimeLimitSetting = {
+    value: number;
+    unit: string;
+};
+
+export function get_time_limit_setting_in_appropriate_unit(
+    time_limit_in_seconds: number,
+): TimeLimitSetting {
+    const time_limit_in_minutes = Math.floor(time_limit_in_seconds / 60);
+    if (time_limit_in_minutes < 60) {
+        return {value: time_limit_in_minutes, unit: "minute"};
+    }
+
+    const time_limit_in_hours = Math.floor(time_limit_in_minutes / 60);
+    if (time_limit_in_hours < 24) {
+        return {value: time_limit_in_hours, unit: "hour"};
+    }
+
+    const time_limit_in_days = Math.floor(time_limit_in_hours / 24);
+    return {value: time_limit_in_days, unit: "day"};
+}