Add startup testing for Wasm Pinecone build (#1910)

* Only include go-sqlite3 on the relevant binaries

* The driver name is always sqlite3 now

* Update to matrix-org/go-sqlite3-js@e537baa

* Add initial Wasm test harness

* Upgrade go-sqlite3-js

This fixes an error about semicolons in single statements.

* Add browser-like WebSocket API for testing

* Upgrade go-sqlite3-js

This upgrade includes printing panic messages next to stacks.

* Run for all PRs targeting any branch

* Use manual Node caching

* Temporarily run for all pushes

* Use npm ci instead of install

* Use HTTPS auth for repo packages

* Match path style from build.sh

* update utp

Co-authored-by: Neil Alexander <neilalexander@users.noreply.github.com>

docs/p2p.md

@@ -2,14 +2,23 @@
 
 These are the instructions for setting up P2P Dendrite, current as of May 2020. There's both Go stuff and JS stuff to do to set this up.
 
-
 ### Dendrite
 
+#### Build
+
 - The `master` branch has a WASM-only binary for dendrite: `./cmd/dendritejs`.
 - Build it and copy assets to riot-web.
 ```
-$ GOOS=js GOARCH=wasm go build -o main.wasm ./cmd/dendritejs
-$ cp main.wasm ../riot-web/src/vector/dendrite.wasm
+$ ./build-dendritejs.sh
+$ cp bin/main.wasm ../riot-web/src/vector/dendrite.wasm
+```
+
+#### Test
+
+To check that the Dendrite side is working well as Wasm, you can run the
+Wasm-specific tests:
+```
+$ ./test-dendritejs.sh
 ```
 
 ### Rendezvous