Add a certificate exercising all supported SAN types

This will be used for comparison in unit tests.
Add a possibility to write certificates with SAN
in cert_write.
Signed-off-by: Andrzej Kurek <andrzej.kurek@arm.com>
diff --git a/tests/data_files/server1.allSubjectAltNames.crt b/tests/data_files/server1.allSubjectAltNames.crt
new file mode 100644
index 0000000..13af873
--- /dev/null
+++ b/tests/data_files/server1.allSubjectAltNames.crt
@@ -0,0 +1,23 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----