m/test/e2e: split out tests into subpackages

The end-to-end tests have grown large enough that they merit their own
test targets. To make this more Go-idiomatic, we split away the tests
not just int separate Bazel targets, but also Go packages.

We also add per-test resource requests for Bazel, including a new
resource kind (iops). This makes the tests more deterministic and allows
use to eg. use --runs_per_test=10 to deflake test logic without hitting
resource contention issues.

//metropolis/test/e2e/suites/core:core_test                              PASSED in 35.1s
  Stats over 10 runs: max = 35.1s, min = 26.6s, avg = 31.9s, dev = 2.6s
//metropolis/test/e2e/suites/ha:ha_test                                  PASSED in 114.6s
  Stats over 10 runs: max = 114.6s, min = 90.1s, avg = 100.9s, dev = 7.6s
//metropolis/test/e2e/suites/ha_cold:ha_cold_test                        PASSED in 67.8s
  Stats over 10 runs: max = 67.8s, min = 55.5s, avg = 62.0s, dev = 4.1s
//metropolis/test/e2e/suites/kubernetes:kubernetes_test                  PASSED in 80.9s
  Stats over 10 runs: max = 80.9s, min = 58.8s, avg = 68.6s, dev = 6.0s

Change-Id: I8f31e09f599fd90c9941e2b69f36789817fa90ce
Reviewed-on: https://review.monogon.dev/c/monogon/+/3086
Reviewed-by: Jan Schär <jan@monogon.tech>
Tested-by: Jenkins CI
diff --git a/.bazelrc b/.bazelrc
index b4de786..5428506 100644
--- a/.bazelrc
+++ b/.bazelrc
@@ -88,3 +88,7 @@
 
 # Load custom per-user settings.
 try-import %workspace%/.bazelrc.user
+
+test --experimental_allow_tags_propagation
+# Assume a 10k IOPS device (average NVMe) and 64GiB of RAM for test scheduling.
+test --local_extra_resources=iops=10000 --local_extra_resources=ram=64000