Support Height Queries in REST Client

[alexanderbez]

Summary

Height queries are now supported in the CLI client via #4382. A similar solution needs to be supported for the REST client.

Namely, each appropriate GET query endpoint will accept a height query param and this value is then passed onto the context.

Essentially the following logic will have to be added to each respective handler:

		heightStr := r.FormValue("height")
		if heightStr != "" {
			height, err := strconv.Atoi(heightStr)
			if err != nil {
				// TODO: handler error
			}
			
			cliCtx = cliCtx.WithHeight(height)
		}

But maybe there is a cleaner way we can do this via middleware to reduce the amount of code we need to write.

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[alexanderbez]

/cc @colin-axner :)