h3i: extract connection creation to its own function #5476

Job	Run time
quiche_macos (macos-13)	4m 9s
quiche_macos (macos-latest)	1m 41s
quiche_windows (x86_64-pc-windows-msvc)	6m 37s
quiche_windows (i686-pc-windows-msvc)	4m 45s
android_ndk_lts (aarch64-linux-android)	1m 0s
quiche_windows (x86_64-pc-windows-gnu)	8m 11s
android_ndk_lts (armv7-linux-androideabi)	59s
quiche_windows (i686-pc-windows-gnu)	5m 59s
docker	3m 11s
android_ndk_lts (x86_64-linux-android)	58s
android_ndk_lts (i686-linux-android)	1m 5s
http3_test	42s
quiche	4m 22s
nginx (1.16.1)	52s
quiche (boringssl-boring-crate)	4m 20s
quiche_ios (x86_64-apple-ios)	1m 8s
quiche (openssl)	7m 15s
quiche_ios (aarch64-apple-ios)	1m 5s
quiche_multiarch (aarch64-unknown-linux-gnu)	3m 10s
quiche_multiarch (armv7-unknown-linux-gnueabihf)	3m 7s
quiche_multiarch (i686-unknown-linux-gnu)	1m 46s
	1h 6m 22s

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