input element isn't suitable for this hack, switch to textarea for
supporting newlines in text to be copied.

Currently error can be reported if email is setup but other than that
only way to find error info is use browser's console.

This change adds a secondary button to copy error info to clipboard.

`message` is used as args in some places and `txt` in another.
Supporting both since there's no clear interface to this arguments for
this component.

fix: Newsletter Enhancements

fix(qb): Miscellaneous fixes

- show published newsletters in list view
- show published newsletter as web page
- show status section after newsletter is sent
- add email_sent_at and total_recipients field

- Cancel Scheduling button
- Show dashboard message if newsletter is scheduled

can be used to clearing events, for e.g., clearing setInterval

- show email sending progress in form dashboard

refactor: module profile

The newsletter content may contain images that get "attached" to the
newsletter document. If this is the case, you can't selectively include
attachments in the newsletter as it attaches all the attachments.
An explicit attachments table solves this problem.

fix: Allow Fetch From for a different link field of the same DocType

problem: if a whitelisted document method returns a falsy value like
`[]`, `{}`, `0` then response.message is not set and not returned
in the response.

this change checks if the return value is `None` and falsy values
are returned properly in the response

mimics python's range function

ability to customize datepicker options via df.options

- Organize fields into sections
- Buttons for Send now and Scheduled sending
- Buttons to Send test email and to Check broken links
- Remove Test section

* [fix] Clarified docstatus transition exceptions

Exceptions issued by the document.py `check_docstatus_transition` method are potentially very misleading. In cases where an invalid docstatus is used, users receive an confusing exception stating "Cannot change docstatus from 0 to 2" or "Cannot change docstatus from 1 to 0". 

This PR adds an additional exception message when an invalid docstatus is used.

* fix: Clarified docstatus transition exceptions

Added additional clarifications to exception messages

fix: Delete Event Producer Last Update on trash event of Event Producer

fix: fixed list of Field objects as fields in get_values

* Update installer.py

* fix: Drop table only if it exists

* revert: "Update installer.py"

This reverts commit 0e8370ede8.

Co-authored-by: Suraj Shetty <surajshetty3416@gmail.com>