Even thought this PR initially aimed with the objective of replacing the "Apm" class inside "src/utils/Apm.ts" file for dappnode's toolkit, as I was replacing it, I realised that this class was only used for resolving ENS names to addresses via it's ethereum Provider parameter, nothing specific to the Aragon Packet Manager.

The only Aragorn Packet Manager related methods are "encodeNewRepoWithVersionCall()" and "encodeNewVersionCall()" (which are not part of the Apm class itself, but are inside the same file).

So, in the end, this PR does the following:

• Delete "Apm" class inside src/utils/Apm.ts and replacing it for utility functions that interact with ENS names. Modified function "getEthereumProviderUrl()" to be exported, added "isValidENSName()" function to check if a ENS is valid before trying to interact with it.
• Refactor of "src/utils/verifyEthConnection.ts" so that it uses only an ethereum provider when checking if provider can connect properly, and not the whole Apm class.
• Integrated toolkint into "src/utils/versions/getNextVersionFromApm.ts"
• Updated tests affected by all the above changes.

Since CI is down atm, I ran all tests locally and passed.

TODO: We should consider adding "encodeNewRepoWithVersionCall()" and "encodeNewVersionCall()" to the dappnode toolkit, and then updating the SDK code again. Also, we should rename "src/utils/Apm.ts" file name, but kept it the same so reviewing this PR is easier