* fetch batch_no in `get_basic_details`
* PEP8 changes and docstring
* only auto-fetch batch number for Sales documents:
otherwise, automatic batch creation will not work properly because all new
stock will be added to old batch
* new function to fetch batch number using FEFO:
FEFO - First Expiring First Out
* fetch batch number in `get_basic_details` using FEFO
* add new function - `set_batch_number`
* `set_batch_number` when `qty` is triggered
* `set_batch_number` when `uom` is triggered
* whitelist `get_batch_no_fefo`
* code clean up
* move `set_batch_number` to conversion_factor instead of uom
* rename `get_batch_no_fefo` to `get_batch_no`
* fix test case
* final cleanup
* Revert "fetch batch_no in `get_basic_details`"
This reverts commit dd024b1eb369eaeafab28165d523fb7a9f8ab8d3.
* fix test case
* update Sales Invoice manual
* move changes away from `transaction.js`
* query should not fetch expired batches
* refactor `get_batch_no`:
add new function `get_batches`
* Update batch.py
