extract upgrade in MsgExecLegacyContent

[MattKetmo]

Currently, only upgrade embedded in SoftwareUpgradeProposal and MsgSoftwareUpgrade are detected.

cosmos-validator-watcher/pkg/watcher/upgrade.go

Lines 218 to 234 in d6945ee

	switch content.TypeUrl {
	case "/cosmos.upgrade.v1beta1.SoftwareUpgradeProposal":
	var upgrade types.SoftwareUpgradeProposal
	err := cdc.Unmarshal(content.Value, &upgrade)
	if err != nil {
	return nil, fmt.Errorf("failed to unmarshal software upgrade proposal: %w", err)
	}
	return &upgrade.Plan, nil
	case "/cosmos.upgrade.v1beta1.MsgSoftwareUpgrade":
	var upgrade types.MsgSoftwareUpgrade
	err := cdc.Unmarshal(content.Value, &upgrade)
	if err != nil {
	return nil, fmt.Errorf("failed to unmarshal software upgrade proposal: %w", err)
	}
	return &upgrade.Plan, nil
	}

But it can also happen via a MsgExecLegacyContent.

Examples:

• https://www.mintscan.io/cosmos/proposals/914
• https://www.mintscan.io/evmos/proposals/303