feat: add freeze & unfreeze extrinsics

[wischli]

Description

• Adds freeze & unfreeze extrinsics
• Adds new Poolrole variant FrozenTrancheInvestor
  • Alternative: Extend existing TrancheInvestor permission with downside of having to migrate all existing storage entries
• Slightly improves docs of pallet-liquidity-pools
• Simplifies and normalizes pallet-liqudiity-pools defensive weights

Checklist:

• [x] I have added Rust doc comments to structs, enums, traits and functions
• [x] I have made corresponding changes to the documentation
• [x] I have performed a self-review of my code
• [x] I have added tests that prove my fix is effective or that my feature works

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 46.88797% with 128 lines in your changes missing coverage. Please review.

Project coverage is 48.31%. Comparing base (4bfeabe) to head (09c4b4c).

Files	Patch %	Lines
runtime/common/src/permissions.rs	0.00%	40 Missing :warning:
pallets/liquidity-pools/src/lib.rs	53.57%	39 Missing :warning:
pallets/liquidity-pools/src/defensive_weights.rs	0.00%	27 Missing :warning:
libs/types/src/permissions.rs	0.00%	15 Missing :warning:
pallets/liquidity-pools/src/tests.rs	95.58%	3 Missing :warning:
pallets/investments/src/lib.rs	50.00%	2 Missing :warning:
pallets/liquidity-pools/src/inbound.rs	33.33%	2 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #1947 +/- ## ========================================== + Coverage 47.83% 48.31% +0.48% ========================================== Files 183 184 +1 Lines 12904 12999 +95 ========================================== + Hits 6172 6281 +109 + Misses 6732 6718 -14 ```

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