Ristretto cache (#2563)

* Try Ristretto cache

* Tweak

* It's beautiful

* Update GMSL

* More strict keyable interface

* Fix that some more

* Make less panicky

* Don't enforce mutability checks for now

* Determine mutability using deep equality

* Tweaks

* Namespace keys

* Make federation caches mutable

* Update cost estimation, add metric

* Update GMSL

* Estimate cost for metrics better

* Reduce counters a bit

* Try caching events

* Some guards

* Try again

* Try this

* Use separate caches for hopefully better hash distribution

* Fix bug with admitting events into cache

* Try to fix bugs

* Check nil

* Try that again

* Preserve order jeezo this is messy

* thanks VS Code for doing exactly the wrong thing

* Try this again

* Be more specific

* aaaaargh

* One more time

* That might be better

* Stronger sorting

* Cache expiries, async publishing of EDUs

* Put it back

* Use a shared cache again

* Cost estimation fixes

* Update ristretto

* Reduce counters a bit

* Clean up a bit

* Update GMSL

* 1GB

* Configurable cache sizees

* Tweaks

* Add `config.DataUnit` for specifying friendly cache sizes

* Various tweaks

* Update GMSL

* Add back some lazy loading caching

* Include key in cost

* Include key in cost

* Tweak max age handling, config key name

* Only register prometheus metrics if requested

* Review comments @S7evinK

* Don't return errors when creating caches (it is better just to crash since otherwise we'll `nil`-pointer exception everywhere)

* Review comments

* Update sample configs

* Update GHA Workflow

* Update Complement images to Go 1.18

* Remove the cache test from the federation API as we no longer guarantee immediate cache admission

* Don't check the caches in the renewal test

* Possibly fix the upgrade tests

* Update to matrix-org/gomatrixserverlib#322

* Update documentation to refer to Go 1.18

.github/workflows/dendrite.yml

@@ -24,7 +24,7 @@ jobs:
       - name: Install Go
         uses: actions/setup-go@v2
         with:
-          go-version: 1.16
+          go-version: 1.18
 
       - uses: actions/cache@v2
         with:
@@ -97,7 +97,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        go: ["1.16", "1.17", "1.18"]
+        go: ["1.18"]
     steps:
       - uses: actions/checkout@v3
       - name: Setup go
@@ -127,7 +127,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        go: ["1.16", "1.17", "1.18"]
+        go: ["1.18"]
         goos: ["linux"]
         goarch: ["amd64", "386"]
     steps:
@@ -160,7 +160,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        go: ["1.16", "1.17", "1.18"]
+        go: ["1.18"]
         goos: ["windows"]
         goarch: ["amd64"]
     steps:
@@ -209,7 +209,7 @@ jobs:
       - name: Setup go
         uses: actions/setup-go@v2
         with:
-          go-version: "1.16"
+          go-version: "1.18"
       - uses: actions/cache@v3
         with:
           path: |