VmBus: allow for port/connection-based SynicPortAccess #1512

Job	Run time
build mdbook guide	1m 25s
build artifacts [x64-linux]	6m 8s
build and check docs [x64-windows]	9m 13s
build openhcl [aarch64-linux]	5m 16s
build openhcl [x64-linux]	7m 35s
clippy [linux, macos], unit tests [x64-linux]	8m 21s
clippy [linux-musl, misc nostd], unit tests [x64-linux-musl]	7m 12s
clippy [windows], unit tests [x64-windows]	11m 30s
unit tests [aarch64-windows]	7m 27s
build and check docs [x64-linux]	2m 52s
test flowey local backend	3m 4s
xtask fmt (linux)	2m 24s
build artifacts (not for VMM tests) [aarch64-windows]	5m 46s
build artifacts (for VMM tests) [aarch64-windows]	8m 52s
build artifacts (not for VMM tests) [x64-windows]	6m 5s
build artifacts (for VMM tests) [x64-windows]	11m 11s
build artifacts [aarch64-linux]	5m 19s
xtask fmt (windows)	5m 42s
run vmm-tests [aarch64-windows]	7m 0s
run vmm-tests [x64-linux]	3m 44s
run vmm-tests [x64-windows-amd]	11m 53s
run vmm-tests [x64-windows-intel]	9m 40s
openvmm checkin gates	8s
	2h 27m 47s

Provide feedback