irc: make Send message dialog multiline and expandable

- Enable  for multiline input.
- Use  and  to expand input box and maximize space.

Signed-off-by: Slendi <slendi@socopon.com>

main.lua

@@ -457,6 +457,9 @@ function IrcChatView:promptSendMessage()
     dialog = InputDialog:new{
         title = _("Send message"),
         input = "",
+        allow_newline = true,           -- allow multiline input
+        use_available_height = true,    -- expand input to available height
+        condensed = true,               -- reduce extra padding to maximize text area
         buttons = {
             {
                 {