enhance: add orphan-checkpoints flag in remove channel

[XuanYang-cn]

Milvus(by-dev) > remove channel --orphan-checkpoints --channel by-dev-rootcoord-dml_0_451952300527190478v0 --force
by-dev-rootcoord-dml_0_451952300527190478v0 selected as target orpah checkpoint, path: by-dev/meta/datacoord-meta/channel-cp/by-dev-rootcoord-dml_0_451952300527190478v0
Milvus(by-dev) > remove channel --channel by-dev-rootcoord-dml_0_451952300527190478v0 --force
by-dev-rootcoord-dml_0_451952300527190478v0 selected as target channel watchinfo, collection id: 451952300527190478
Milvus(by-dev) > remove channel --channel by-dev-rootcoord-dml_0_451952300527190478v0
Milvus(by-dev) > remove channel --orphan-checkpoints --channel by-dev-rootcoord-dml_0_451952300527190478v0
Milvus(by-dev) > remove channel --orphan-checkpoints

[sre-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

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[XuanYang-cn]

[XuanYang-cn]

https://github.com/milvus-io/milvus/issues/35588