Run gofmt on dendrite - apply go 1.17 preferred build tags

[PiotrKozimor]

Go 1.17 introduces new way to add build tags - see release notes, section //go:build lines. Running gofmt -w . in Dendrite directory yields changes in this PR. Apparently, golangci-lint run fails because of that with output below (assuming go 1.17). I didn't find an option to configure it and make it non fatal. This failing logs are annoying when linting locally. We also should catch up witch language changes.

syncapi/storage/storage.go:14: File is not `goimports`-ed (goimports)

roomserver/storage/storage.go:14: File is not `goimports`-ed (goimports)

internal/sqlutil/postgres.go:14: File is not `goimports`-ed (goimports)

internal/sqlutil/trace_driver.go:14: File is not `goimports`-ed (goimports)

federationsender/storage/storage.go:14: File is not `goimports`-ed (goimports)

mediaapi/storage/storage.go:14: File is not `goimports`-ed (goimports)

cmd/dendritejs/main_noop.go:14: File is not `goimports`-ed (goimports)

appservice/storage/storage.go:14: File is not `goimports`-ed (goimports)

userapi/storage/accounts/storage.go:14: File is not `goimports`-ed (goimports)

userapi/storage/devices/storage.go:14: File is not `goimports`-ed (goimports)

signingkeyserver/storage/keydb.go:14: File is not `goimports`-ed (goimports)

mediaapi/thumbnailer/thumbnailer_nfnt.go:14: File is not `goimports`-ed (goimports)

cmd/dendrite-demo-pinecone/embed/embed_other.go:1: File is not `goimports`-ed (goimports)
// +build !elementweb
cmd/dendrite-demo-yggdrasil/embed/embed_other.go:1: File is not `goimports`-ed (goimports)
// +build !elementweb
cmd/dendritejs-pinecone/main_noop.go:14: File is not `goimports`-ed (goimports)

keyserver/storage/storage.go:14: File is not `goimports`-ed (goimports)

Pull Request Checklist

• I have added any new tests that need to pass to sytest-whitelist as specified in docs/sytest.md
• Pull request includes a sign off

Signed-off-by: Piotr Kozimor <p1996k@gmail.com>