[cli] [etcd2] Migrate etcd2topo flags to pflags

[rsajwani]

Signed-off-by: Rameez Sajwani rameezwazirali@hotmail.com

Description

Updates topo related flag references specified in #10859

$ go list -f '{{ .ImportPath }}| {{ join .Deps " " }} ' ./go/cmd/... | awk -F"|" '$2 ~ "vitess.io/vitess/go/vt/topo/etcd2topo" {print $1}'
vitess.io/vitess/go/cmd/topo2topo
vitess.io/vitess/go/cmd/vtbackup
vitess.io/vitess/go/cmd/vtcombo
vitess.io/vitess/go/cmd/vtctl
vitess.io/vitess/go/cmd/vtctld
vitess.io/vitess/go/cmd/vtgate
vitess.io/vitess/go/cmd/vtgr
vitess.io/vitess/go/cmd/vtorc
vitess.io/vitess/go/cmd/vttablet
vitess.io/vitess/go/cmd/vttestserver
vitess.io/vitess/go/cmd/zk

Related Issue(s)

closes #10859

Checklist

• "Backport me!" label has been added if this change should be backported
• Tests were added or are not required
• Documentation was added or is not required

Deployment Notes

[vitess-bot]

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