Remove amino converter workaround

[ryanchristo]

This issue tracks the removal of the amino converter workaround and is dependent on upstream fixes.

In #69, a workaround was implemented to support amino. In summary, the amino converters for several messages used within the application were not handling undefined values, which is how amino translates zero-values. We override the amino converters from the regen-js api pacakge (i.e. @regen-network/api) with custom amino converters in src/api/group.amino.ts.

In order to create custom amino converters, we had to import types from the src directory within the api package. The types are not available in the types directory because the code within the src directory includes typescript errors (regen-network/regen-js#84) and therefore will not compile. We had to manual resolve some typescript errors within src (which will be overwritten on running codegen) and tag a release with manual changes (i.e. v1.0.0-alpha5, which includes regen-network/regen-js#79 and regen-network/regen-js#87) in order to run and build the groups application without upstream typescript errors.

Another thing to be aware of, and depending on the upstream solution, when we remove the amino converter workaround, we may need a solution for amino support with MsgSubmitProposal similar to what was proposed in cosmology-tech/telescope#281 for messages that create and update a group policy. The type we need for MsgSubmitProposal is currently unavailable but also may not be necessary depending on the upstream solution. The partial implementation is included in #69.