This commit introduces the ability to dump the complete content of an
account to a JSON file (compact or not depending on the provided format
option).
Example:
```sh
solana account -u m \
--output json-compact \
--output-file SRM_token.json \
SRMuApVNdxXokk5GT7XD5cUUgXMBCoAz2LHeuAoKWRt
```
Note: Behavior remains untouched if format option `--output` is not
provided (only account data gets written to file).
0e9e67b65d