Accept character set and collation info during `dolt init`

`dolt init` does not support specifying a character set or collation. And dolt does not yet support [ALTER DATABASE](https://dolt.gitbook.io/dolt-dev/sql-reference/sql-support/supported-statements#data-definition-statements), so if we want a DB with a specific character set or collation, it has to be done through SQL:
```bash
dolt sql -q "CREATE DATABASE db CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci;"
```