Provide a full solution for long comments breaching the character limit

Problem

Long comments in JIRA can cause performance problems as investigated on JRA-28519
There is a jira.text.field.character.limit set to 32767 by default in JIRA Cloud.
This prevents the saving of a comment with a message:

The entered text is too long. It exceeds the allowed limit of 32767 characters.

At that point the user needs to either remove characters or copy the text already formatted on the comment to a text file, save it locally and attach it to the issue.

Steps to reproduce

1. In a comment paste some text with more than 32767 characters
2. Click Save
3. Observe the error

We couldn't save your comment

The comment is too long. Try reducing its length, splitting it, or attaching a file to the issue.

# Observe that the comment itself looks similar to a saved one except for the Alert icon:

1. Refresh the page - the comment will have disappeared.

Suggestion

Provide a full user friendly alternative when saving comments that go over the limit to improve the speed and convenience. e.g Provide a feature to automatically convert huge text into a file and attach is as an issue attachment.

An idea:

JIRA prompts to save the long text in an attachment.
Example:

The entered text is too long. Would you like us to create a file attachment with text inside the text blocks?

JIRA then parse the {code} and {noformat} text into a .txt file and attaches it to the issue.
Then it adds the comment with the text that was outside the blocks, adds a preview of the blocks text and a link to the attachment containing the full text. If multiple blocks are find, then it does a different file for each one.

More info

This has been previously asked/requested on:

• https://answers.atlassian.com/questions/16392971/what-is-the-best-way-to-hide-large-text-in-jira-issue-description
• https://jira.atlassian.com/browse/JRA-59124