[develop < T0106] fix @property being optional when they are not

[brunos252]

Description

After @BorisTasevski noted checking for None in a property that is not of type Optional[...] is not consistent, I looked at other @property uses.

• for NodePartialQuery and RelationshipPartialQuery value argument, which is optional, I turned the double negative if-else expression into positive logic, as we previously discussed was easier to understand.
• for arguments labels and properties, along with RemovePartialQuery and DeletePartialQuery arguments, I removed the checking and Optional support since they go through their respective to_cypher_ methods first, which assigns them an empty string if they are None to begin with. This is something to discuss, if you think we should still support this for flexibility (e.g. if we were to change to_cypher_properties method), let me know.

One other thing I noticed: RelationshipPartialQuery receives a labels argument, but we agreed on naming the relationship labels as types. and also, there must be exactly one so it should be named type. Unfortunately this would be a breaking change.

Pull request type

• Code style update (formatting, renaming)

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

######################################

Reviewer checklist (the reviewer checks this part)

• Core feature implementation
• Tests
• Code documentation
• Documentation on memgraph/docs

######################################

[BorisTasevski]

Please let's iterate over this one more time on Monday.