fix(047): the initial csource notification (TS 104-175 clause 12.4.7)

The initial notification of a context source registration subscription.

Spec: TS 104-175 clause 12.4.7: "the csource notification shall be sent on initial subscription and whenever there is a change in a matching csource registration" - also when no registration matches yet, with an empty data array.

Change:

• 047_03, 047_04, 047_07 consume the initial notification, so their later waits see the notification they are about.
• 047_05 checks the bookkeeping of that initial notification (timesSent, no failure), and that a registration that does not match sends nothing more (1-timesSent-failed.json updated).
• 047_02 and 047_04 register Building and Bus (context-source-registration-building-and-bus-entities.jsonld), so the notified registration ids are the ones the Test Case created.
• Check Notification Data Entities (NotificationUtils) accepts an entityInfo type as a string or an array of strings - indexing [0] into a string gave its first character.

Effect (against coraine): 047_02_01, 047_03_01, 047_04_01, 047_06_01, 047_07_01, 047_07_02 fail on develop and pass with this MR. 047_01_01 and 047_05_01 pass on both. None breaks. 047_08 to 047_16 need the same change - the next MR, stacked on this one.

Checks run: robocop format --check (0 files), scripts/find_unused_test_data.py (nothing new), statisticsDocumentationData.py (0 of 625 failed), doc unit tests OK.

Fix MR 10 of the plan: https://famzang.com/ttf/ngsi-ld-suite-plan.html