[fix] #802 fix ""Send as source" not displayed in context menu on standard condition received transaction

Add test on parse_transaction_doc()

Fix test

HeadV2 now get all properties from Head, HeadV0 and HeadV1

Check is source exists before display menu

add custom function "total_amount" to test db

Refactor tests of evaluate_condition in test_sources.py
Update tests

Fix tests

This is to avoid using locked sources

Need all the tx referenced by the sources in the db !

Fix the previous commit that add complex and potentially locked sources in db

Dropping sources and recreate them from tx inputs was loosing source conditions.
This consume method allow to not loose source and their conditions

Upgrade database automatically to version 8
Remove source drop and restore from inputs as it quite impossible to retrieve source conditions from inputs

Add lock_mode depending on selected lock condition
- Receiver signature
- Receiver signature OR (issuer after one week)

Change "to send" style from bold to italic