Sort namespaces, mounts, and clients before adding them to HLL

[miagilepner]

Description

Sort the activity log clients before adding them to the hyperloglog to ensure consistent results.

Performance:

$ VAULT_TEST_LOG_DIR=$(mktemp -d) go test -bench=^BenchmarkLargeClientCount$  -tags="ent enterprise testonly" $(pwd)/vault/external_tests/activity_testonly -run "^$" -benchmem 
goos: darwin
goarch: arm64
pkg: github.com/hashicorp/vault/vault/external_tests/activity_testonly
BenchmarkLargeClientCount/10000_per_mount-10                  18          56399891 ns/op        32806902 B/op      50671 allocs/op
BenchmarkLargeClientCount/100000_per_mount-10                  2         762893583 ns/op        207117244 B/op    465944 allocs/op
BenchmarkLargeClientCount/500000_per_mount-10                  1        5710724250 ns/op        1496278752 B/op  2420449 allocs/op
BenchmarkLargeClientCount/1000000_per_mount-10                 1        17837094792 ns/op       2983561024 B/op  4837697 allocs/op
BenchmarkLargeClientCount/2000000_per_mount-10                 1        38098365375 ns/op       5959903936 B/op  9690766 allocs/op
PASS
ok      github.com/hashicorp/vault/vault/external_tests/activity_testonly       145.191s

what's currently on main:

$ VAULT_TEST_LOG_DIR=$(mktemp -d) go test -bench=^BenchmarkLargeClientCount$  -tags="ent enterprise testonly" $(pwd)/vault/external_tests/activity_testonly -run "^$" -benchmem 
goos: darwin
goarch: arm64
pkg: github.com/hashicorp/vault/vault/external_tests/activity_testonly
BenchmarkLargeClientCount/10000_per_mount-10                  22          55692903 ns/op        32134565 B/op      50655 allocs/op
BenchmarkLargeClientCount/100000_per_mount-10                  2         781777021 ns/op        201372028 B/op    466613 allocs/op
BenchmarkLargeClientCount/500000_per_mount-10                  1        5563718292 ns/op        1467175480 B/op  2418694 allocs/op
BenchmarkLargeClientCount/1000000_per_mount-10                 1        11221255292 ns/op       2925794392 B/op  4835923 allocs/op
BenchmarkLargeClientCount/2000000_per_mount-10                 1        23813339459 ns/op       5842432544 B/op  9666556 allocs/op
PASS
ok      github.com/hashicorp/vault/vault/external_tests/activity_testonly       125.793s

Ent PR: https://github.com/hashicorp/vault-enterprise/pull/6369

TODO only if you're a HashiCorp employee

• Labels: If this PR is the CE portion of an ENT change, and that ENT change is
  getting backported to N-2, use the new style backport/ent/x.x.x+ent labels
  instead of the old style backport/x.x.x labels.
• Labels: If this PR is a CE only change, it can only be backported to N, so use
  the normal backport/x.x.x label (there should be only 1).
• ENT Breakage: If this PR either 1) removes a public function OR 2) changes the signature
  of a public function, even if that change is in a CE file, double check that
  applying the patch for this PR to the ENT repo and running tests doesn't
  break any tests. Sometimes ENT only tests rely on public functions in CE
  files.
• Jira: If this change has an associated Jira, it's referenced either
  in the PR description, commit message, or branch name.
• RFC: If this change has an associated RFC, please link it in the description.
• ENT PR: If this change has an associated ENT PR, please link it in the
  description. Also, make sure the changelog is in this PR, not in your ENT PR.

[github-actions]

CI Results:
All Go tests succeeded! ✅

[github-actions]

Build Results:
All builds succeeded! ✅

[VioletHynes]

Looks good! Small comment on the changelog but non-blocking

[VioletHynes]

I think this should be improvement? change is usually reserved for breaking changes or things that might affect an existing workflow.

[miagilepner]

good point, updated