FEATURE Several attempts to run Crowdin CLI

[dshiryaev-plesk]

Hello,
Thank you for your work!
Crowdin has moved their CLI in version v3 to Crowdin API v2. Crowdin API v2 works unstable, so does Crowdin CLI v3. These changes adds an ability to recall Crowdin CLI several times with an exponential backoff in case Crowdin CLI fails. The default values for the backoff:

- backoff_max_attempts:	3
- backoff_exp_base:		8

Example for .serge config:

sync
{
    ts
    {
        plugin      crowdin
        data
        {
            backoff_max_attempts	3
    		backoff_exp_base		8
        }
    }
}

Can, you consider these changes to merge, please ?

[dragosv]

@dshiryaev-plesk I would prefer to rename backoff to retry (so backoff_max_attempts will be retry_max_attempts). As well there are no new tests for the new functionality, while the existing ones are failing. Plus I would like the defaults for the new values to be retry_max_attempts to be 1. As well a better name should be used for backoff_exp_base (It is not clear what it represents)