fix: fixes cache leak and unhandled promise rejection

[achingbrain]

Fixes some bugs in the new request cache:

1. When stopping the client we were supposed to remove the response cache, instead we were deleting an item from the cache
2. When stopping we were voiding the cache deletion - this can cause unhandled promise rejections so switches to awaiting the promise instead
3. When starting the cache was being created asynchronously but without waiting for the promise to resolve, so you could stop the client before the cache was intialized which would mean it is never cleaned up

Also not a bug but it also makes the cache name configurable.

Change checklist

• [x] I have performed a self-review of my own code
• [ ] I have made corresponding changes to the documentation if necessary (this includes comments as well)
• [x] I have added tests that prove my fix is effective or that my feature works

[2color]

Btw, are you certain that we call start in consumers of the client (Helia and libp2p)?

• For Helia, my understanding is that it happens here: https://github.com/ipfs/helia/blob/1aa6c8d93edb779d2e5668081fb847314b2e2c79/packages/utils/src/routing.ts#L32
• For js-libp2p, my understanding is that it happens here: https://github.com/libp2p/js-libp2p/blob/4d59c801a6b45dcc0b2d7b457b4ae3b107b57cbb/packages/libp2p/src/components.ts#L88

[achingbrain]

Yes, we call .start and .stop from the locations you link to.

[achingbrain]

Also sorry for not getting to the review of #151 in time, this PR is me doing it post-merge.

[github-actions[bot]]

:tada: This PR is included in version @helia/delegated-routing-v1-http-api-client-v4.2.1 :tada:

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot :package::rocket: