[Deployments] Add Flags to the Environment struct

Add an ability to pass any set of command line flags throughout the executions.
Example flag: --dry-run.

deployment/environment.go

@@ -76,6 +76,7 @@ type Environment struct {
 	Chains            map[uint64]Chain
 	NodeIDs           []string
 	Offchain          OffchainClient
+	Flags             map[string]string
 }
 
 func NewEnvironment(
@@ -135,6 +136,10 @@ func (e Environment) AllDeployerKeys() []common.Address {
 	return deployerKeys
 }
 
+func (e Environment) SetFlag(key, value string) {
+	e.Flags[key] = value
+}
+
 func ConfirmIfNoError(chain Chain, tx *types.Transaction, err error) (uint64, error) {
 	if err != nil {
 		//revive:disable