Lose ChainId in Provider

[tabaktoni]

Is your feature request related to a problem? Please describe.
get-starkness implement ChainId instead of StarknetChainId

/**
 * chain id, given in hex representation.
 * @pattern "^0x[a-fA-F0-9]+$"
 */
export type ChainId = string;

The definition is in starkness-types

Users can set any custom L2/L3 chain ID

Describe the solution you'd like
Accordingly to this as Dhruv suggested Starknetjs should also support adding custom chain ID
This should be enabled/refactored on Provider

Describe alternatives you've considered
There is no alternative (level restrained as it is)

Additional context
get-starknet
starknet-types

[princeibs]

I would like to hop on this @tabaktoni