fix(bonding_manager): fix validation of epoch when bonding/unbonding

[kerber0x]

Description and Motivation

This PR improves the validation when bonding/unbonding so it makes sure not only that a new epoch has been created but that the system is up to date, i.e. if an epoch is due to be created the contract won't let you bond or unbond.

Related Issues

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Checklist:

• [x] I have read Migaloo's contribution guidelines.
• [x] My pull request has a sound title and description (not something vague like Update index.md)
• [x] All existing and new tests are passing.
• [x] I updated/added relevant documentation.
• [x] The code is formatted properly cargo fmt --all --.
• [x] Clippy doesn't report any issues cargo clippy -- -D warnings.
• [x] I have regenerated the schemas if needed cargo schema.

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 95.65217% with 6 lines in your changes missing coverage. Please review.

Project coverage is 90.92%. Comparing base (2f40957) to head (8670d58). Report is 1 commits behind head on release/v2_contracts.

Files	Patch %	Lines
...s/liquidity_hub/bonding-manager/src/tests/suite.rs	57.14%	3 Missing :warning:
...acts/liquidity_hub/bonding-manager/src/contract.rs	96.42%	1 Missing :warning:
...racts/liquidity_hub/bonding-manager/src/helpers.rs	94.73%	1 Missing :warning:
...s/liquidity_hub/bonding-manager/src/tests/claim.rs	95.45%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## release/v2_contracts #371 +/- ## ======================================================== + Coverage 90.90% 90.92% +0.02% ======================================================== Files 280 280 Lines 31830 31917 +87 ======================================================== + Hits 28936 29022 +86 - Misses 2894 2895 +1 ```

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[github-actions[bot]]

Schema generation had missing jobs:

contracts/liquidity_hub/bonding-manager/schema/bonding-manager.json
contracts/liquidity_hub/bonding-manager/schema/raw/execute.json

Please run just schemas locally and upload the generated schemas.

[github-actions[bot]]

Schema generation had missing jobs:

contracts/liquidity_hub/bonding-manager/schema/bonding-manager.json

Please run just schemas locally and upload the generated schemas.