scoutcloud improvements 02

features for gelato

add new config variables: https://www.notion.so/blockscout/c2eb5ebd57e548c1b7f677df76703728?v=78feefe69e6c42b59d21879d96722c41 (all with PLANNED status)
stats: https://blockscout.slack.com/archives/C06RWV75C04/p1715270950437889?thread_ts=1715258287.916539&cid=C06RWV75C04 add stats_enabled variable that checks /api/v2/main-page/indexing-status of current blockscout and enabled status if indexing is finished
use health check as a status. e.g. after PENDING it should be either RUNNING or UNHEALTHY (new status) depending on health status
add current deployment information into the /instance handle

Add endpoint POST /api/v1/users/profile:register to create profile with initial api key add optional field promo that allow registration with non empty balance. Test promo value can be obtained from @sevenzing
Add endpoint GET/POST /api/v1/users/auth-tokens to create api-key and list current api-keys

update default domain for instance from <instance_name>.k8s-dev.blockscout.com to <instance_name>.cloud.blockscout.com