v8.0rc1: first release candidate for v8

8.0-rc1

This release introduces support for Taproot descriptors on Bitbox02 devices and
a new install process including set-up templates and examples.
The way the wallet displays its syncing state was reworked.

Breaking changes
================

Running Liana v8 on an existing installation will migrate its database.
Once migrated the database won't be compatible with previous versions of Liana.
This means you won't be able to open with Liana v7 (or below) any wallet opened or created with Liana v8.

The new Minimum Supported Rust Version of the GUI software is now 1.71.1. This change was necessary to include
the new Bitbox02 rust client version.

Features
========

Liana daemon / library

A new field `last_poll_timestamp` was added to the wallet table in order to track the last time the wallet
was updated by the poller.

Liana GUI

- The new Bitcoind 28.0 version is now downloaded by the GUI.
- Bitbox02 devices can now be part of a Taproot descriptor set-up if their firmware version is greater than or equal to 9.21.0.
- The install process now includes examples of setups with fixed templates and explanatory descriptions to guide the user.
- UI/UX of the GUI buttons was reworked to have a clear distinction between a primary and a secondary button.
- The way the wallet displays its syncing state was reworked to follow these expected outcomes:

| ****Backend type****                | ****Wallet type****                                 | ****Expected outcome****                                                                                                             |
| ----------------------------------- | --------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------ |
|   Liana Connect                     |   Creating a new wallet / Adding an existing wallet |   Show “Syncing…” with balance blinking until the first poll (we check the wallet height becomes positive)                           |
|   Liana Connect                     |   Loading a wallet already present in datadir       |   No syncing behavior expected                                                                                                       |
|   Local bitcoind (managed or not)   |   Creating a new wallet / Adding an existing wallet |   IBD progress bar (if needed). No syncing behavior expected.                                                                        |
|   Local bitcoind (managed or not)   |   Loading a wallet already present in datadir       |   No blockchain syncing progress bar, jump directly to the wallet.  Show "Syncing blockchain (X%) until blockchain synced. After that, show "Checking for new transactions..." until the first poll.   |
|   Electrum                          |   Creating a new wallet / Adding an existing wallet |   Show “Syncing…” with balance blinking until the first poll                                                                         |
|   Electrum                          |   Loading a wallet already present in datadir       |   Show "Syncing blockchain (X%) until blockchain synced. After that, show "Checking for new transactions..." until the first poll.   |
|   External daemon                   |   Creating a new wallet / Adding an existing wallet |   IBD progress bar (if needed). No syncing behavior expected                                                                         |
|   External daemon                   |   Loading a wallet already present in datadir       |   If last poll timestamp was already set once, will show "Checking for new transactions..."                                          |

Fixes
=====

Liana GUI

- Hardware wallets with the app not open had a confusing warning message about outdated version.
- Button for the pagination of past transactions was sometimes missing because of a wrong calculation of the page size.
- Resend authentication token request did not work for already created account.