RESTAKING + VAULT: Adding Metadata Admin Field

[coachchucksol]

In the future we will have a metadata account for the vaults, operators and ncns. I think it makes sense to keep the admin to update this metadata within it's respective account and this keeps our pattern of separation of authority.

Side effect: This metadata_admin consumed the reserve buffer in the middle of the accounts. Which is good to clean it up a bit

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 52.56410% with 37 lines in your changes missing coverage. Please review.

Project coverage is 82.36%. Comparing base (2b9e831) to head (1de5713). Report is 2 commits behind head on master.

Files with missing lines	Patch %	Lines
restaking_program/src/ncn_set_secondary_admin.rs	0.00%	13 Missing :warning:
restaking_core/src/ncn.rs	75.00%	8 Missing :warning:
vault_core/src/vault.rs	64.28%	5 Missing :warning:
vault_program/src/set_secondary_admin.rs	0.00%	4 Missing :warning:
restaking_core/src/operator.rs	70.00%	3 Missing :warning:
...taking_program/src/operator_set_secondary_admin.rs	0.00%	3 Missing :warning:
restaking_core/src/config.rs	50.00%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #130 +/- ## ========================================== - Coverage 82.42% 82.36% -0.07% ========================================== Files 86 86 Lines 8685 8847 +162 ========================================== + Hits 7159 7287 +128 - Misses 1526 1560 +34 ```

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[coachchucksol]

I added in two additional ncn admins: weight_table_admin and ncn_program_admin

I am anticipating the needs of the weight_table and the bespoke ncn on-chain's program's need to be verifiably tied to the ncn struct.