imp(ibc-testkit): remove field access of MockContext

[rnbguy]

Closes: #1043

Description

Removes ctx.events or context.events access from the tests.

This PR also moves .events and .logs fields under MockIbcStore to keep them under Arc<Mutex<MockIbcStore>>.

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PR author checklist:

• Added changelog entry, using unclog.
• Added tests.
• Linked to GitHub issue.
• Updated code comments and documentation (e.g., docs/).
• Tagged one reviewer who will be the one responsible for shepherding this PR.

Reviewer checklist:

• Reviewed Files changed in the GitHub PR explorer.
• Manually tested (in case integration/unit/mock tests are absent).

[Farhad-Shabani]

Thanks @rnbguy. Just a quick note about this change:

My understanding so far, an IBC module usually should not autonomously store any events and logs. I know it is so in the basecoin-rs, but rationally, the storage access in IBC is designed to be either provable or private, serving the purpose of maintaining a record of IBC states as outlined in the specs.

Hosts typically maintain a sort of pool that collects dispatched events and logs from various modules and different parts of the system. Then the aggregated arrays would be included in the response of a transaction. Though, to achieve this, we should decouple storage from keys, so fields in IbcMockStore would act as mappers instead of having instant access to the store. Nevertheless, for now, we are fine with this change.

[rnbguy]

Totally see your point. But my view is that, since we are working in the context of the IBC module, I see them as effects of the IBC module. So, to simplify things, I wanted to put everything that IBC affects - stores, logs, events; in one unified struct.