Split @iov/tendermint-types

@iov/tendermint-types somehow became home of very generic types we use everywhere. But it should be possible to use IOV-Core without Tendermint-chains and without the term “tendermint” in packages.

In there we currently have

// keys
enum Algorithm
type PrivateKeyBytes
interface PrivateKeyBundle
type PublicKeyBytes
interface PublicKeyBundle

// network
type ChainId

// transactions
type SignatureBytes
interface SignatureBundle
type PostableBytes
type TxId
interface TxQuery
interface Tag

Tendermint types used by tendermint:

Type name	used in @iov/tendermint-rpc	used in @iov/bcp-types	used in @iov/bns
Algorithm	✅	(implicitly in PublicKeyBundle)	✅
PrivateKeyBytes	-	-	✅
PrivateKeyBundle	-	-	✅
PublicKeyBytes	✅	(implicitly in PublicKeyBundle)	✅
PublicKeyBundle	✅	✅	✅
ChainId	✅	✅	✅
SignatureBytes	✅	✅	✅
SignatureBundle	✅	-	-
PostableBytes	✅	✅	✅
TxId	✅	✅	✅
TxQuery	✅	✅	✅
Tag	✅	✅	✅

Ideas for improvements:

1. Tag and TxQuery should be split to allow having different types in BcpConnection and in @iov/tendermint-rpc: TendermintQueryTag / BcpQueryTag and TendermintTxQuery / BcpTxQuery.
2. PrivateKeyBytes and PrivateKeyBundle should move to @iov/bns and should not be exported as they are only used in bns codec tests
3. Make SignatureBundle available in @iov/tendermint-rcp only and rename to VoteSignatureBundle

The rest can go to a package called @iov/base-types for now.

[webmaster128]

I found a nice way to move buildTxQuery(query: BcpTxQuery): QueryString into @iov/bns and keep a simple buildTagsQuery(tags: ReadonlyArray<QueryTag>): QueryString for internal use in @iov/tendermint-rpc

[webmaster128]

Extracted https://github.com/iov-one/iov-core/issues/520, the rest is done. The result makes me very happy.