Indicator for counting bytes of currently typed characters in the chat box

[zebraed]

As an addition to the fixes implemented in #751, an indicator will be added to improve UX.
When a user types a chat approaching the character (byte) limit, an indicator will display in chatbox.

if the input text is too long, the limit will be enforced (Max 150 char on UTF-8 Byte)
However, if the byte count is exceeded due to copying and pasting, the text will not be truncated.
Instead, the message will be prevented from sending, notifying the user of the character limit violation.