refactor!: Virtual DocType

Co-authored-by: gavin <gavin18d@gmail.com>

Assigning a function to a different name breaks inheritance model.

E.g. doc.reload() won't call virtual doctype's load_from_db but call
original load_from_db

Current APIs implement class methods as instance method, which is
problamamtic while implementing methods. E.g. If load_from_db doesn't
like empty docname then all class method will stop working.

This change while breaking is essential for usability of virtual
doctype.

refactor!: Database

Co-authored-by: Ankush Menat <ankushmenat@gmail.com>

There existed inconsistencies between db_query & db's fallback for min
datetime in str format - missing decimal seconds places. Now, we're
storing the default string once and re-using it to reduce
inconsistencies or room for human errors.

db.default_port wil be available as a class attribute to hold defaults
for DB types.

Usage: frappe.conf.db_port or frappe.db.default_port
Why: I couldn't run the mariadb command because the defaults aren't set
for my system. server is remote / containerized. Setting port in
equivalent mysql command fixes this.

This is supposed to be a temporary switch to make the parent PR easier
to digest. MariaDB client has some issues with release, and system
dependencies.

This commit may be reverted to enable mariadb client again.

* ci: bump node version to node16

* chore: remove `node-sass` - no longer used

Co-authored-by: Sagar Vora <sagar@resilient.tech>

* fix: ensure 2FA patch sets parent only for 2FA keys

* fix: try to rebuild defaults

* fix: set other app defaults as well

* fix: set POS profile defaults

* fix: exists params

* chore: remove unnecessary change

* fix: handle case where POS Profile doesnt exist

* chore: move erpnext code to erpnext

feat: Undo/Redo changes on FormView

if both values are same then logging it doesn't make much sense.

This commit implements basic undo/redo on form view fields

fix: Query for unseen notification

style: use `middleware` decorator to keep function definition intact

fix: No need to check for permission again while attaching a file