Properly handle/enforce GROUP_NAME_MAX_CHAR on group settings page

[dotmacro]

Problem

On the Group Settings page, the text box for the group name has no char limit in the UI. However, there's clearly an enforced limit on the backend because the error message indicates that groupName cannot exceed 50 chars.

Solution

Fix, presumably by handling GROUP_NAME_MAX_CHAR the same here as during group creation.

[dotmacro]

Additionally, "You can report the error" in the error message is not a link, and not clickable. @taoeffect Should #1945 be reopened, or is this a new issue?

[SebinSong]

@dotmacro

Additionally, "You can report the error" in the error message is not a link, and not clickable. @taoeffect Should #1945 be reopened, or is this a new issue?

You can see them as separate issues as those are two different UI components. I can handle that bug as part of this task.