feat: multi sync example

[Viktor-Kalashnykov-da]

Multi-Synchronizer DvP Example - On ledger API - Part 1

Showcases automatic reassignment of Token from private synchronizer to global one, used on a realistic trade scenario with use of a custom Token.

New test:
https://github.com/canton-network/wallet/pull/1622/changes#diff-37db720ea457076fe6d04f6938d19c44e5dde3d7e1a5815953ff6b83199a1052

Design principles:

1. !!! We remove handling of synchronizers inside wallet-sdk.
   Client code should be responsible of selecting synchronizerId in multi-sync scenarios.
   If not provided - synchronizer choice is left for canton participant logic.
   Existing tests are updated (refactor(wallet-sdk): remove default synchronizer auto-selection #1740).

2. We try to show "realistic scenario" - we use multiple parties (Alice, Bob, TokenAdmin, TradingApp) we also
   distribute dars to selected synchronizers (private dars to private). This contributes to relative complexity of the test code

source:
https://docs.google.com/presentation/d/1q6LpHi-wC_MO_mzf7wp5D-15j4lNeKjCMW5xmBggaTY

3. Example works with Token Standard V1
   We have experimented with token standard V2 -> but as V2 is not yet merged to splice use of V2 means even more code

4. All tests run on multi-sync

This is a first PR in a series
Showcases only on-ledger part - and ensures code works.
There are 2 follow up PRs (wip)

• off ledger api for tokens standard Implementation feat: multi sync example test token token standard api implementation #1782
  (code extracted and merged here)
• rework of synchronizerId refactor(wallet-sdk): remove default synchronizer auto-selection #1740 - (choice of synchronizer removed from wallet sdk)

Technical limitations:
In this PR we introduce separate tests for multi-sync (otherwise regular tests are flaky on multi-sync) - that split will be removed in a separate PR (above)

New example script:
docs/wallet-integration-guide/examples/scripts/15-multi-sync-trade.ts

Notes

1. explicit reassignment
   we experimented with automatic reassignment of contracts - and it basically worked BUT.

It worked as long as Bob is owner of TokenRules contract which seems unrealistic.
We introduced TokenAdmin as additional party that is issuer of Token on app-synchronizer (private one).
But this in fact forces us to use explicit reassignment.

2. TestToken on global synchronizer. The original intention seemed to be that TestToken dar is only vetted on private synchronizer.
   But since the settlement actually happens on global - TestToken related models must be also on global synchronizer

[jarekr-da]

I made first round or review.
Generally that is a scenario we want.
I posted questions and problems to recheck / fix.

[meiersi-da]

@jarekr-da @mjuchli-da @mateuszpiatkowski-da : I've done another high-level review. As you can see from my comments I'm still a bit worried about missing a problem due to

1. not using a one-participant-per-party topology
2. not relying on automatic reassignments, which is what ultimately want to promote.

How do you propose to address these two concerns?

[mateuszpiatkowski-da]

From my side: some of the minor issues listed here are already fixed, the rest of them is either implemented here: #2383 or moved as a follow-up task: #2391. @jarekr-da will also contribute by creating a PR to this branch implementing some stuff from his side.

[jarekr-da]

responded to changes -
PR with review issues
#2387