e2e for WebClient

[maksimryndin]

depends on #148

we need to create a test (up to the tx signing and submission) for app/crates/platforms/web/src/client.rs

basically test main flows - deposit, transfer, withdraw (possible transact?)
we should use stellar-cli to deploy new contracts on the testnet (using scripts/deploy.sh)
then create 2 accounts
add them to asp set etc
...

so it is a complete smoke test (except tx submission and signing - to be added later - see also #162)

this e2e test will be run before any new redeployment of the app