Cypher query access to parameter that is a dictionary inside the list

Hi I'm completely new to the graph db so probably not very difficult question, but would appreciate if someone can help me with the following:
i have a node labeled X with property "Tags" with the value of
{"key": "Name", "Value": "someName"},
{"Key": "Owner" , "Value": "someOwner"}

the tag owner it isn't always present

is there a way that i can match all nodes X with the tag "Owner" not being "someOwner" or if it tag "Owner" doesn't exist?

How are you setting that value to a property? I though Neo4j only supports primitive values or arrays of the same.

Can you just store these values as independent properties, such as:
Create(n:X {Name: "someName", Owner: "someOwner"})

If so, it would be easy to find nodes where Owner being null or not equalling "someOwner"

to add to @glilienfield approach, at this time Neo4j does no support indexing of arrays/maps etc. So if you record the value as-is from the original post then we wouldnt be able to use an index to improve performance. @glilienfield answer would allow one to index said properties