test(mcms): optimise container startups

The original tests which include spinning up solana containers take up a good chunk of time

```
github.com/smartcontractkit/cld-changesets/legacy/mcms/changesets	112.753s	coverage: 67.1% of statements
github.com/smartcontractkit/cld-changesets/mcms/changesets/set-config	133.902s	coverage: 91.2% of statements
github.com/smartcontractkit/cld-changesets/mcms/solana/changesets/fund-mcm-pdas	60.253s	coverage: 89.7% of statements
```

I have since optimised it by doing:
- reduce container startups by having multple tests share the same container if there are no conflicts
- reduce duplicate tests in the sequence or operation tests when the same flow has been covered by the integration test at changeset_test.go

Author: graham-chainlink

internal/testutil/solanatest/datastore.go

@@ -0,0 +1,42 @@
+// Package solanatest provides test utilities for Solana MCMS integration tests.
+package solanatest
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/smartcontractkit/chainlink-deployments-framework/datastore"
+	mcmscontracts "github.com/smartcontractkit/chainlink-deployments-framework/engine/cld/contracts/mcms"
+
+	"github.com/smartcontractkit/cld-changesets/internal/semvers"
+	"github.com/smartcontractkit/cld-changesets/legacy/pkg/family/solana/solutils"
+)
+
+// NewDataStoreWithMCMSPrograms seeds a datastore with canonical MCMS program IDs.
+// The test validator preloads the same programs via WithSolanaContainer; program
+// deploy is skipped because artifacts lack -keypair.json files required by
+// solana program deploy for fixed program IDs.
+func NewDataStoreWithMCMSPrograms(t *testing.T, selector uint64) datastore.DataStore {
+	t.Helper()
+
+	v := semvers.V1_0_0
+	ds := datastore.NewMemoryDataStore()
+	for _, entry := range []struct {
+		addr string
+		ct   datastore.ContractType
+	}{
+		{solutils.GetProgramID(solutils.ProgAccessController), datastore.ContractType(mcmscontracts.AccessControllerProgram)},
+		{solutils.GetProgramID(solutils.ProgMCM), datastore.ContractType(mcmscontracts.ManyChainMultisigProgram)},
+		{solutils.GetProgramID(solutils.ProgTimelock), datastore.ContractType(mcmscontracts.RBACTimelockProgram)},
+	} {
+		require.NoError(t, ds.Addresses().Add(datastore.AddressRef{
+			ChainSelector: selector,
+			Address:       entry.addr,
+			Type:          entry.ct,
+			Version:       &v,
+		}))
+	}
+
+	return ds.Seal()
+}