[WIP] Remove useless cache locks in LRUs

[v4lproik]

What type of PR is this?
Enhancement
Bug fix

What does this PR do? Why is it needed?

• This PR does several things:
• Update the hashicorp LRU cache to the latest stable version
• Implement a better contract between caches / callers allowing homogenous code to be reused across the different types of cache (miss/hit prom metrics to be consistent, same behaviour when value not found in cache, have the same controls when inserting into the cache eg. nil value are not allowed... etc)
• Fix some bugs along the way

Which issues(s) does this PR fix?
#13723

Other notes for review

[nisdas]

As a general rule, it would be much easier to review these changes if you split it into different PRs by each specific cache. Some of these are on critical paths, so being able to review them independently is important. Also in the event any change breaks something we can simply revert the PR to the specific cache rather than for all the caches.

[v4lproik]

You are absolutely correct. I have kept this PR as a work in progress because it has grown larger than what is typically acceptable, as you pointed out.

However, I have kept it for a few reasons:

• Firstly, I am consistently testing the changes locally to ensure that I am not inadvertently breaking anything at runtime or having odd results/errors.
• Secondly, I wanted to ensure that implementing lru/v2 at a low level with generics for each cache using the new interface would be feasible.

I have broken down the commits per service to make it easier for me to cherry-pick the changes on a per-PR basis. Could you please indicate which cache you would like to see this implementation for in the first review as I am nearly finished?

Thank you!

[nisdas]

@v4lproik I have no preference on the order of caches to review. Feel free to open PRs in any order you would like

[v4lproik]

@nisdas I have opened the rework of the Committees Cache if you want to have a look at it.