Pruning mode crash during block indexing

During the block indexing, the plugin will crash because it shares the info with esplora in get info chain, but in the next command that the plugin receives it will crash because we have no method to check that the bitcoin core is not ready.

So a possible solution is to check the type of exception and if the exception is like fo following one, check the bitcoin status in downloading mode or adding a new proprieties in the plugin manager.

Return command example

```
error code: -28
error message:
Loading block index...
```