relax `XcmFeeToAccount` trait bound on `AccountId` (#4959)

Fixes #4960 

Configuring `FeeManager` enforces the boundary `Into<[u8; 32]>` for the
`AccountId` type.

Here is how it works currently: 

Configuration:
```rust
    type FeeManager = XcmFeeManagerFromComponents<
        IsChildSystemParachain<primitives::Id>,
        XcmFeeToAccount<Self::AssetTransactor, AccountId, TreasuryAccount>,
    >;
```

`XcmToFeeAccount` struct:
```rust
/// A `HandleFee` implementation that simply deposits the fees into a specific on-chain
/// `ReceiverAccount`.
///
/// It reuses the `AssetTransactor` configured on the XCM executor to deposit fee assets. If
/// the `AssetTransactor` returns an error while calling `deposit_asset`, then a warning will be
/// logged and the fee burned.
pub struct XcmFeeToAccount<AssetTransactor, AccountId, ReceiverAccount>(
	PhantomData<(AssetTransactor, AccountId, ReceiverAccount)>,
);

impl<
		AssetTransactor: TransactAsset,
		AccountId: Clone + Into<[u8; 32]>,
		ReceiverAccount: Get<Acco...