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/CertificateIssuer/CERT_CI_ECDSA_BRP.pem

@@ -0,0 +1,15 @@
+-----BEGIN CERTIFICATE-----
+MIICUTCCAfigAwIBAgIJALh086v6bETTMAoGCCqGSM49BAMCMEQxEDAOBgNVBAMM
+B1Rlc3QgQ0kxETAPBgNVBAsMCFRFU1RDRVJUMRAwDgYDVQQKDAdSU1BURVNUMQsw
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+f5u5Ce6DVC2oIfpn5UnS24F3oMqM
+-----END CERTIFICATE-----