getLegacyDatabaseLocation: Change message.

[nalepae]

What type of PR is this?
Other

What does this PR do? Why is it needed?
Some users complained on Discord that the message displayed when the validator client DB was found in the legacy
location was too scary.

This PR:

• Changes this message from WARNING to INFO
• Remove the "please move..." mention
• Add more context

Example of message:

[2024-01-16 10:53:36]  INFO node: Database not found in the --datadir directory (/Users/manu/Library/Eth2)
		but found in the --wallet-dir directory (/Users/manu/Library/Eth2Validators/prysm-wallet-v2/direct),
		which was the legacy default.
		The next time you run the validator client without a database,
		it will be created into the --datadir directory (/Users/manu/Library/Eth2).
		To silence this message, you can move the database from (/Users/manu/Library/Eth2Validators/prysm-wallet-v2/direct/validator.db)
		to (/Users/manu/Library/Eth2/validator.db).