Reorganize packages

[corbanbrook]

As discussed during our Retreat this is an initial attempt at reorganizing the existing sequence.js workspace packages so that they are grouped by their use case.

• packages/0xsequence - A package that reexports all other packages for ease of use and e2e integration tests
• packages/tests - A package that contains test setups and fixtures used by other packages
• packages/wallet/* - Packages that are used specifically to build a wallet like the wallet-webapp
• packages/dapp/* - Packages that are used by dapp developers to integrate sequence
• packages/common/* - Packages that are shared between wallet and dapp
• packages/apis/* - Packages that relate to sequence apis (Api, Indexer, Metadata)

NOTE: This doesn't change the build tooling, the names of the packages on npm, or how packages function, it is merely an organizational effort within the repo to help convey to developers what packages are important for their use case.