Initial proof-of-concept SM-DP+ for GSMA consumer eSIM RSP

This commit introduces

* the osmo-smdpp.py program implementing the main procedures and the
  HTTP/REST based ES9+
* python modules for ES8+ and non-volatile RSP Session State storage
* the ASN.1 source files required to parse/encode RSP
* 3GPP test certificates from SGP.26
* an unsigned profile package (UPP) of a SAIP v2.3 TS48 test profile

As I couldn't get the 'Klein' tls support to work, the SM-DP+ code
currently does not support HTTPS/TLS but plan HTTP, so you either have
to modify your LPA to use HTTP instead of HTTPS, or put a TLS proxy in
front.

I have successfully installed an eSIM profile on a test eUICC that
contains certificate/key data within the test CI defined in GSMA SGP.26

Change-Id: I6232847432dc6920cd2bd08c84d7099c29ca1c11

smdpp-data/certs/DPauth/PK_S_SM_DP2auth_ECDSA_NIST.pem

@@ -0,0 +1,4 @@
+-----BEGIN PUBLIC KEY-----
+MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEKy6bRdNRwJr0DpFDg6GQOEfyYH3m
+DverJcQOA/jbtlCOFFdQjCvgAXNH7Pob+fd159B+gF5S4ZiLe1hacRGuMw==
+-----END PUBLIC KEY-----