Make getExplorerInfo return values per network

[nicosampler]

In a discussion related to how to deal with getExplorerInfo (it's a function that returns the explorer URL to inspect an address or transaction). Pablo and I suggested that we should have a separate file in order to define all the functions that should handle a particular case depending on the current network.

The intention was that at the moment of creating a new network, a developer should go to src/config folder and replicate all the existing files with the new network. Giving it a second thought I think it is an overkill, at the moment getExplorerInfo it's the only function that needs a special treatment depending on the network.

Another alternative is to create another file utils.ts (?) where we can handle all these particular cases, but we will end having an index.ts and a utils.ts where won't be crystal what's the purpose of each one.

What I suggest to do is to make a little refactor in the current getExplorerInfo. That's what this PR does.

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Type	Occurrences	Fixable
Errors	0	0
Warnings	0	0
Ignored	1	N/A

• Result: ✅ success
• Annotations: 0 total

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