NodeJs: sweet improvements :strawberry:

[Alex6323]

Description of change

This PR:

• ~adds a new WalletError variant: AliasMismatch { provided: String, expected: String };~
• ~returns that error in case a provided alias conflicts with the one stored in the wallet db;~

UPDATE: after a call we decided to remove this alias mismatch detection from this PR, because we don't think there's a real problem with the builder overwriting the alias stored in the db since this is non-critical data. I kept the other changes unrelated to the wallet alias, which are:

• NodeJs: consistency changes and improve wallet.spec.ts tests

Links to any relevant issues

Fixes #2016

How the change has been tested

Integration tests.

[DaughterOfMars]

Shouldn't we just overwrite it? I mean it's just an alias.

[Alex6323]

Shouldn't we just overwrite it? I mean it's just an alias.

could maybe be used to trick someone to enter the stronghold password ... I would be conservative here and not do that. I'ld rather have some explicit command that says change_alias or something (similar to change_stronghold_password).