Add cache hit/miss rate

Any call to cache that doesn't return data (null) is treated as a miss. We define a span that has a cache hit as having the span data field cache.hit as true. Might require SDK to patch cache abstractions of framework (django).

To be done in Python SDK for any frameworks that support this - django is required.

### Cache hit/miss rate
- [ ] https://github.com/getsentry/develop/pull/917
- [ ] https://github.com/getsentry/sentry-python/issues/2043

Add db platform data to to span data

Add this information to span data field as db.system, matching OpenTelemetry's well known conventions.

For example, db.system of postgresql would indicate that it's a postgres database.

### DB platform data.
- [ ] https://github.com/getsentry/develop/pull/917
- [ ] https://github.com/getsentry/sentry-python/pull/2035
- [ ] https://github.com/getsentry/sentry-javascript/pull/7952
- [ ] https://github.com/getsentry/sentry-python/pull/2037
- [ ] https://github.com/getsentry/sentry-python/pull/2038
- [ ] https://github.com/getsentry/sentry-python/pull/2039
- [ ] https://github.com/getsentry/sentry-python/pull/2040
- [ ] https://github.com/getsentry/sentry-python/pull/2042

Add cache item size

Add a field to cache spans that defines how big the item that is being get/set: cache.item_size. This is an integer and should be in bytes. Blocked by cache hit/miss rate work.

### Cache Item size
- [ ] https://github.com/getsentry/develop/pull/933
- [x] Add `cache.item_size` to Python SDK

Add information used for action field

The action field on the extracted span metrics is either the operation for DB spans (SELECT/DELETE etc.), and http method for HTTP spans (GET/PUT etc.).

For operation, we'll be using and setting db.operation on span data. For http method, we'll be using http.method on span data.

If db.operation OR http.method is not set on span data, Relay will have to parse it out from the span description.

### Action
- [ ] https://github.com/getsentry/develop/pull/924
- [ ] https://github.com/getsentry/sentry-python/pull/2053
- [ ] https://github.com/getsentry/sentry-python/pull/2054
- [ ] https://github.com/getsentry/sentry-javascript/pull/7990
- [ ] https://github.com/getsentry/sentry-javascript/pull/7991