fix: unnecessary restrictions on memo validation

[beer-1]

Issue Description

Many IBC applications and middlewares rely on the memo field to pass arbitrary messages for their application logic. However, Orbiter currently blocks memos that use root-level keys other than its own. Unless there is a strong reason to enforce this restriction, removing this validation would allow other IBC applications to interoperate with Orbiter without issues.

orbiter/controller/adapter/generic_parsers.go

Lines 59 to 64 in 97bef41

	if len(jsonData) != 1 {
	return nil, core.ErrParsingPayload.Wrapf(
	"json data contains multiple root level keys, accepted only %s",
	core.OrbiterPrefix,
	)
	}