Sandbox scripts migration from bash to Go

[BupycHuk]

Currently the scripts used to start the sandbox and set the replicasets are written in bash.
We need to re-write this in Go

https://github.com/percona/mongodb_exporter/blob/main/docker/scripts/init-shard.sh
https://github.com/percona/mongodb_exporter/blob/main/docker/scripts/setup.sh

Those two files still require non-trivial knowledge of bash in addition to Go and MongoDB knowledge for anyone who would like to contribute. They also require a local installation of MongoDB CLI – something we should not require.

[RISHIKESHk07]

hey @BupycHuk was interested in the project , would like to contribute

[BupycHuk]

@RISHIKESHk07, sure, please, go ahead