improve contacts, fix typedefs, v4 decode

[KraXen72]

• improve contacts handling (convert old format into new one)
• fix type defs -> depends on https://github.com/minibits-cash/cashu-ts/pull/2 being merged or the changes implemented on the version of cashu-ts we will decide to use.
  • until this is merged, i changed the version in package.json to my fork. when that will be merged, i will revert that change.
• implemented token v4 decoding
  • i have tested the decoding both by pasting a v3 and v4 token, and by scanning a v3 and v4 token (tokens taken from the spec, added cashu:// and pasted into an online qr-code generator). everything works, except token v4 warns about no currency info, so it defaults to sats.

REQUIRED:

• check if we need to do any steps in https://github.com/cashubtc/cashu-ts/blob/main/migration-1.0.0.md
• this pull request depends on https://github.com/minibits-cash/cashu-ts/pull/5 being merged and then the version of @cashu/cashu-ts to be changed back to the minibits fork.

[KraXen72]

for this pull request to be merged, whichever version of cashu-ts we end up using, will need to include the modifications to the type definitions i made in https://github.com/minibits-cash/cashu-ts/pull/1.

[KraXen72]

ah hej ja som tam dodal dalsie ltska lebo node 18 uz je out of date a ja pouzivam 22 (latest) - nemal som s tym ziadne problemy.