Add new parameter skip_munging for rabbitmq_parameter

[joec4i]

Pull Request (PR) description

Add new parameter skip_munging for rabbitmq_parameter to prevent numberic strings from being converted to integers.

This Pull Request (PR) fixes the following issues

We have several x-content-hash exchanges which use a numeric string as the routing key. As a result, shovels for these exchanges would include key value pairs like this "src-exchange-key": "5". By default the string "5" will be converted to an integer. However, RabbitMQ doesn't accept exchange keys to be integers. As a result, we'd run into errors from RabbitMQ

Error:
Validation failed
dest-exchange-key should be binary, actually was 5
src-exchange-key should be binary, actually was 5

This PR would allow the auto type conversion to be disabled and therefore numeric strings to be included in the RabbitMQ parameter payload if needed.

[joec4i]

Closing this in favour of voxpupuli#865