feat(wallet): add Liquid Auth provider

[HashMapsData2Value]

Adds Liquid-Auth-Js (abstracted behind Liquid-Auth-Use-Wallet-Client, name open to change!), to allow for the demo Liquid Auth Android app to be used for demonstrative purposes. Similar to the Wallet Connect example wallet/provider.

Liquid Auth requires a backend-api which is included in this PR. Namely, the liquid-auth-backend examples folder. It comes with a docker compose yaml file with instructions on how to set things up using Ngrok to host the Liquid Auth backend and tunnel through to a URL accessible publicly provided by Ngrok.

The docker-compose also includes an Nginx container that, besides doing reverse proxy stuff, also hosts the static files generated the example frontends. By default it is the vanilla-ts that is hosted.

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Examples:

• vanilla-ts, vue-ts, react-ts and solid-ts: all of these work as expected
• nextjs: Issues with server-side rendering
• nuxt: haven't adjusted for lack of dist folder

[HashMapsData2Value]

As mentioned privately, the BaseWallet's signTransaction method has an _indexesToSign argument. Because there are no examples I have not been sure how to best implement this.

The current implementation simply maps through the tx:s:

https://github.com/algorandfoundation/liquid-auth-use-wallet-client/blob/63eafc5477014aaf8c056c546f3ff076c51985b4/src/LiquidAuthClient.ts#L144

[drichar]

The indexesToSign argument is optional and can be omitted when using signTransactions.

It exists as an optional "filter" only if you want to tell the wallet which specific transactions you want the user to sign.

Each transaction in the group is inspected and only marked for signature if:

1. it is unsigned
2. the signer account is currently active or connected
3. indexesToSign is undefined, OR it contains the transaction's index

If any of those conditions are false then it will not be presented for signature.

[HashMapsData2Value]

Hi @drichar, as we spoke on Discord it is optional and it's handled internally within the use-wallet-client repo so I believe it can be left to the side for now.