fix: set landed cost based on purchase invoice rate (backport #45947)

[mergify]

Reference support ticket 31369

The feature "Set Landed Cost Based on Purchase Invoice Rate" was not considering quantity of items when calculating the new incoming rate.

Note: This PR contains a patch

---

This is an automatic backport of pull request #45947 done by Mergify.

[mergify]

Cherry-pick of 17d415b has failed:

On branch mergify/bp/version-15-hotfix/pr-45947
Your branch is up to date with 'origin/version-15-hotfix'.

You are currently cherry-picking commit 17d415b105.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Changes to be committed:
	modified:   erpnext/controllers/buying_controller.py
	modified:   erpnext/stock/doctype/purchase_receipt/purchase_receipt.py
	new file:   erpnext/stock/doctype/purchase_receipt_item/patches/__init__.py
	new file:   erpnext/stock/doctype/purchase_receipt_item/patches/recalculate_amount_difference_field.py
	new file:   erpnext/stock/doctype/purchase_receipt_item/patches/rename_field_from_rate_difference_to_amount_difference.py
	modified:   erpnext/stock/doctype/purchase_receipt_item/purchase_receipt_item.py

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   erpnext/accounts/doctype/purchase_invoice/test_purchase_invoice.py
	both modified:   erpnext/patches.txt
	both modified:   erpnext/stock/doctype/purchase_receipt_item/purchase_receipt_item.json

Cherry-pick of 154e981 has failed:

On branch mergify/bp/version-15-hotfix/pr-45947
Your branch is ahead of 'origin/version-15-hotfix' by 3 commits.
  (use "git push" to publish your local commits)

You are currently cherry-picking commit 154e9813c4.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Changes to be committed:
	modified:   erpnext/stock/doctype/purchase_receipt_item/patches/recalculate_amount_difference_field.py
	modified:   erpnext/stock/doctype/purchase_receipt_item/patches/rename_field_from_rate_difference_to_amount_difference.py

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   erpnext/patches.txt

Cherry-pick of 1230127 has failed:

On branch mergify/bp/version-15-hotfix/pr-45947
Your branch is ahead of 'origin/version-15-hotfix' by 4 commits.
  (use "git push" to publish your local commits)

You are currently cherry-picking commit 1230127d24.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Changes to be committed:
	renamed:    erpnext/stock/doctype/purchase_receipt_item/patches/recalculate_amount_difference_field.py -> erpnext/patches/v15_0/recalculate_amount_difference_field.py
	renamed:    erpnext/stock/doctype/purchase_receipt_item/patches/rename_field_from_rate_difference_to_amount_difference.py -> erpnext/patches/v15_0/rename_field_from_rate_difference_to_amount_difference.py
	deleted:    erpnext/stock/doctype/purchase_receipt_item/patches/__init__.py

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   erpnext/patches.txt

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally