[sdk/python] improved vectors generation

[gimre-xymcity]

What's the issue?

There's a lot of repetitions and lot of senseless cases (mostly) in symbol tx test vectors

How have you changed the behavior?

• converted "generate" functions to "recipes
• removed duplicates
• removed senseless cases
• introduced new cases, mostly oriented around flags covering

How was this change tested?

• previous change ([sdk/python] task: generate test vectors (part 1) #99 verified that generator actually emits proper payloads,
• this change introduces new vectors, existing (py) vector tester passes on all of them (haven't checked js, should pass as well)

[Jaguar0625]

1. lint is failing: https://jenkins.symboldev.com/blue/organizations/jenkins/Symbol%2Fgenerated%2Fsymbol%2Fpython/detail/PR-118/5/pipeline
2. do we need _new file prefix still?

[lgtm-com]

This pull request introduces 3 alerts when merging 6c86df7 into ae6375e - view on LGTM.com

new alerts:

• 3 for Unused import

[gimre-xymcity]

merged into feature branch