This PR is centered around a main fix regarding the base deposit and a
bunch of drive by or related fixtures that make sense to resolve in one
go. It could be broken down more but I am constantly rebasing this PR
and would appreciate getting those fixes in as-one.

**This adds a multi block migration to Westend AssetHub that wipes the
pallet state clean. This is necessary because of the changes to the
`ContractInfo` storage item. It will not delete the child storage
though. This will leave a tiny bit of garbage behind but won't cause any
problems. They will just be orphaned.**

## Record the deposit for immutable data into the `storage_base_deposit`

The `storage_base_deposit` are all the deposit a contract has to pay for
existing. It included the deposit for its own metadata and a deposit
proportional (< 1.0x) to the size of its code. However, the immutable
code size was not recorded there. This would lead to the situation where
on terminate this portion wouldn't be refunded staying locked into the
contract. It would also make the calculation of the deposit changes on
`set_code_hash` more complicated when it updates the immutable data (to
be done in #6985). Reason is because it didn't know how much was payed
before since the storage prices could have changed in the mean time.

In order for this solution to work I needed to delay the deposit
calculation for a new contract for after the contract is done executing
is constructor as only then we know the immutable data size. Before, we
just charged this eagerly in `charge_instantiate` before we execute the
constructor. Now, we merely send the ED as free balance before the
constructor in order to create the account. After the constructor is
done we calculate the contract base deposit and charge it. This will
make `set_code_hash` much easier to implement.

As a side effect it is now legal to call `set_immutable_data` multiple
times per constructor (even though I see no reason to do so). It simply
overrides the immutable data with the new value. The deposit accounting
will be done after the constructor returns (as mentioned above) instead
of when setting the immutable data.

## Don't pre-charge for reading immutable data

I noticed that we were pre-charging weight for the max allowable
immutable data when reading those values and then refunding after read.
This is not necessary as we know its length without reading the storage
as we store it out of band in contract metadata. This makes reading it
free. Less pre-charging less problems.

## Remove delegate locking

Fixes #7092

This is also in the spirit of making #6985 easier to implement. The
locking complicates `set_code_hash` as we might need to block settings
the code hash when locks exist. Check #7092 for further rationale.

## Enforce "no terminate in constructor" eagerly

We used to enforce this rule after the contract execution returned. Now
we error out early in the host call. This makes it easier to be sure to
argue that a contract info still exists (wasn't terminated) when a
constructor successfully returns. All around this his just much simpler
than dealing this check.

## Moved refcount functions to `CodeInfo`

They never really made sense to exist on `Stack`. But now with the
locking gone this makes even less sense. The refcount is stored inside
`CodeInfo` to lets just move them there.

## Set `CodeHashLockupDepositPercent` for test runtime

The test runtime was setting `CodeHashLockupDepositPercent` to zero.
This was trivializing many code paths and excluded them from testing. I
set it to `30%` which is our default value and fixed up all the tests
that broke. This should give us confidence that the lockup doeposit
collections properly works.

## Reworked the `MockExecutable` to have both a `deploy` and a `call`
entry point

This type used for testing could only have either entry points but not
both. In order to fix the `immutable_data_set_overrides` I needed to a
new function `add_both` to `MockExecutable` that allows to have both
entry points. Make sure to make use of it in the future :)

---------

Co-authored-by: command-bot <>
Co-authored-by: cmd[bot] <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: PG Herveou <pgherveou@gmail.com>
Co-authored-by: Bastian Köcher <git@kchr.de>
Co-authored-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>