fix(Treatment Counselling): Add payment entry on_cancel and paid amount calculation (backport #514)

[mergify]

• Correction in calculation of total amount in Treatment Counselling
• Handle payment entry on_cancel event
• Supports partial payment

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  This is an automatic backport of pull request fix(Treatment Counselling): Add payment entry on_cancel and paid amount calculation #514 done by Mergify.

[mergify]

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Unmerged paths:
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	deleted by us:   healthcare/healthcare/custom_doctype/payment_entry.py
	deleted by us:   healthcare/healthcare/doctype/treatment_counselling/treatment_counselling.py
	both modified:   healthcare/hooks.py

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