Add graphman unassign/reassign commands to graphman graphql api #9004

Job	Run time
Subgraph Runner integration tests	8m 30s
Check rustfmt style	5s
Clippy linting	2m 46s
Run integration tests	10m 37s
Build in release mode	2m 47s
Run unit tests	7m 24s
	32m 9s

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