[MongoDB] Add verbosity level support to `explain`

[sapter]

This is a feature request. Currently the explain tool only supports the default verbosity level (thanks @gagik for adding it in #18 ). It would be really helpful to be able to specify the verbosity level such as executionStats. This is really useful when prototyping aggregation pipeline design and optimizations.

Thanks!

[github-actions]

Thanks for opening this issue. The ticket MCP-183 was created for internal tracking.

[gagik]

Hey, thank you for raising this! That definitely would make a lot of sense and we'll keep track of this for a future update.