Before there were 2 separate fn calls in the 'src/main.rs' module:

    let session = context::connect(conf).await?;
    let session = Context::new(session);

With this change we simplify it the way that we will do only one call:

    let session = context::connect(conf).await?;

With this change it is now possible to configure retry approach for queries.
Following new options are available:

  --retry-number=10
  --retry-interval=200ms | --retry-interval=100ms,3s
  --request-timeout=5

The '--retry-number' option allows to configure number of retries to be applied
in case of query failures. Default is '10'.

The '--retry-interval' option may store one or two time values separated
with comma.
Values may have 'ms' (milliseconds), 's' (seconds) units.
If 2 are specified then it will be 'minimum' and 'maximum' waiting interval
with exponential growth based on the made attempts. Default is '100ms,5s'.

The '--request-timeout' allows to configure the time for a query after which
it is considered as 'failed'. Measured in seconds. Default is '5'.

Print only 5 retry error messages per sample interval.
Also, hide long 'string' and 'blob' values from the retry error messages.