Attachments, Protected Shares, Efficient Sync, and more

[sgwilym]

A huge branch of interrelated and breaking changes for Earthstar v10 Squirrel.

• Adds attachments, so Earthstar can store large arbitrary binary data (thank you @achou11 for Node FS attachment drivers!)
• Add share keypairs, so shares can have granular read write access
• Add efficient sync (thank you for your help @AljoschaMeyer!)
• New event APIs
• Added a faster Sodium crypto driver
• Added a fast Sqlite FFI driver
• Improved querying performance (thank you for your help @basham!)
• Added a common API for modifying a client's settings
• Syncing a share's contents with the filesystem now supports large files
• Multiformat support in replicas
• Closes Access-controlled workspaces (invite-only) #7
• Closes Efficient sync #12
• Closes Sync over duplex stream #15
• Closes Sparse mode: handle documents without their actual content #33
• Closes Change some validator methods from private to public #43
• Closes When docs expire, we need to send a change event #58
• Closes A better way to handle binary data #61
• Closes Specify max size limit for Earthstar documents #89
• Closes Decrease web bundle size #216
• Closes QueryFollower: think about deletions and expired docs #223
• Closes Storage should emit more events #226
• Closes QueryFollower: support limit #225
• Closes Events for ephemeral deletion #220
• Closes Write a new QueryFollower that uses web streams #219
• Closes Use external superbus, superbus-map #217
• Closes Add sodium driver #218
• Closes QueryFollower: allow the query to use historyMode: 'latest' #222
• Closes [Deno] create a lockfile #224
• Closes Bundling issues with Snowpack #233
• Closes Docs not being synced despite salted handshake success #240
• Closes Replica eraseExpiredDocs() is called too frequently #254
• Closes Performance issues with queryDocs() #255
• Closes Upsert documents in bulk #256
• Closes ReplicaCache needs new Replica methods #265
• Closes Web sync partner names should be switched #266
• Closes Add pre-bundled Replica drivers #267
• Closes Make Earthstar select the best crypto driver for the detected platform #268
• Closes Cancel attachment transfers when syncing is cancelled #270

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• Resolve merge conflicts
• Get CI passing again.
• Last scan for jsdocs
• Update CHANGELOG
• Do a big rewrite of README. Conceptual explanations of how syncing works; storage; attachments.