fix(models): wire RealitioWithdrawBonds SharedState into composed MRO (crash-loop fix)

[jmoreira-valory]

Same crash-loop fix as market-resolver#35, applied to market-creator

After the resume-after-timeout claim cache (omen_realitio_withdraw_bonds_abci v0.1.2, cascaded via #230) merged, market-creator main was left in the same crash-prone state the resolver hit in production: the composed market_maker_abci.SharedState does not include the withdraw-bonds sub-skill in its MRO, so realitio_claim_build_cache is never initialised on the runtime self.context.state.

RealitioWithdrawBondsBehaviour._build_claim_txs reads it directly:

```
AttributeError: 'SharedState' object has no attribute 'realitio_claim_build_cache'
-> AEAActException -> skill_exception_policy: stop_and_exit -> Propel restart loop
```

The market-creator deployment was not yet bumped to the cache CID (the agent-deployments env bump was held), so this is a pre-deploy fix — no production impact, unlike the resolver.

Fix — standard repo pattern

The composed SharedState already multiply-inherits MechInteractSharedState and CtRedeemTokensSharedState so their __init__ cross-round vars (ignored_ct_positions, mech state) land on the runtime state. This adds RealitioWithdrawBondsSharedState alongside them:

```python
class SharedState(
MechInteractSharedState,
BaseSharedState,
CtRedeemTokensSharedState,
RealitioWithdrawBondsSharedState, # <- added
):
```

The class docstring is updated to spell out the invariant (omitting a sub-skill whose behaviour reads self.context.state.<attr> crash-loops).

Verification

```
instantiate composed SharedState -> realitio_claim_build_cache == {} (next to ignored_ct_positions)
```

Test plan

• TestSharedState (4) incl. new regression (attr initialised + sub-skill in MRO)
• market_maker_abci suite 58 passed
• lint green (isort/black/flake8/mypy/pylint/darglint)
• structural green (check-abciapp-specs/handlers/packages)
• autonomy packages lock cascade; third_party preserved

Rollout

Merge → service CID bafybeibb5msj3gggv2clat37k4vfpalsjr6bveym3ve6ty64ean3tpgpzy. The held agent-deployments creator env bumps (QS + Pearl) must target this fixed CID, not #230's.

[OjusWiZard]

Approve — minimal, well-targeted crash-loop fix.

• MRO is sound: RealitioWithdrawBondsSharedState is appended last, so it can't override any previously-resolved method; its only effect is contributing __init__ to the cooperative super() chain (same mechanism as ignored_ct_positions).
• Regression test asserts both MRO membership and realitio_claim_build_cache == {} after real instantiation — the right pair of assertions for this bug class.
• Import follows the file's existing force_single_line isort convention.
• Hash cascade is internally consistent (skill CID matches aea-config; agent CID matches service.yaml; service CID matches the rollout CID in the PR body).
• Docstring now documents the invariant.

LGTM.