Starknetjs v6 Strategy

[tabaktoni]

We are currently at pre-release v5.22.0 RPC 0.4 with multiple incoming changes.
Moving forward I propose this plan:

1. (NOW) Release the final v5 version with:

• deprecated Sequencer provider (already done in pre-release)
• deprecate the default provider with a common interface (between Sequencer and RPC)
• RPC 0.5
• Deprecations & Default RPC Provider #809 (still had sequencer but the default is RPC)

2. Cumulative changes for v6:

• [V6] WalletAccount #792
• 1. Remove Sequencer provider (create new Service Provider with still existing endpoints ??? use-case: someone wants to create an RPC node in nodejs or bun or some other extravaganzas)
• 2. Remove the common interface and make the default provider === rpc provider
• 3. (13/11/2023) Add RPC 0.6 as an additional RPC provider default implementation and keep both specks (0.5 and 0.6)
• Release v6 with all these changes

Steps 2.1 and 2.2 will open space to support multiple RPC Specs at the same time.

[tabaktoni]

V6

• Provider: ProviderInterface now use only rpc, server as the backward compatible provider (minimal change)
• RpcProvider detached from ProviderInterface, serves pure rpc responses, removed deprecated (most of the changes)
• Mixin to introduce external libs like StarknetId into base Class (in this case RpcProvider) This will allow externalization of its code to separate package and allow any additional packages with similar requirements
• Refactor test for new setup
• Updated ProviderInterface with channel for re-instantiation from existing instance
• Updated ProviderInterface with rpc spec demanding changes
• RpcProvider implements ProviderInterface
• Provider is now an alias of RpcProvider
• Introduces RpcChannel as the lowest pure RPC channel
• Refactor RpcProvider to be Provider Interface to the underlying spec implementation inside channel

[tabaktoni]

• RPC Fee estimation does not have skipValidate! Removing skipValidate from interface and all usages

[tabaktoni]

• Extract Sequencer to be Service instead of Provider
• Clean Sequencer service and leave only 0.13+ supported endpoints