Harden grep key ID calls

Key IDs may accidentally match dig output that is not the key ID (for
example the RRSIG inception or expiration time, the query ID, ...).
Search for key ID + signer name should prevent that, as that is what
only should occur in the RRSIG record, and signer name always follows
the key ID.
41 jobs for !1836 with matthijs-fix-dnssec-test-intermittent-failure-kskonly in 15 minutes and 54 seconds (queued for 3 seconds)
detached
Status Job ID Name Coverage
  Precheck
passed #219324
linux amd64
🐞:sid:amd64

00:00:15

passed #219323
linux amd64
misc:sid:amd64

00:00:18

 
  Build
passed #219335
linux amd64
asan:sid:amd64

00:01:12

passed #219336
linux amd64
clang:stretch:amd64

00:01:21

passed #219337
linux i386
clang:stretch:i386

00:01:39

passed #219325
linux amd64
docs:sid:amd64

00:00:46

passed #219334
linux amd64
gcc:bionic:amd64

00:01:13

passed #219326
linux amd64
gcc:centos6:amd64

00:02:03

passed #219327
linux amd64
gcc:centos7:amd64

00:02:12

passed #219332
linux amd64
gcc:fedora29:amd64

00:02:00

passed #219328
linux amd64
gcc:jessie:amd64

00:01:19

passed #219330
linux amd64
gcc:sid:amd64

00:01:33

passed #219331
linux i386
gcc:sid:i386

00:01:18

passed #219329
linux amd64
gcc:stretch:amd64

00:01:30

passed #219333
linux amd64
gcc:xenial:amd64

00:01:21

passed #219338
linux amd64
pkcs11:sid:amd64

00:01:10

 
  Test
passed #219357
linux amd64
system:asan:sid:amd64

00:07:48

passed #219355
linux amd64
system:gcc:bionic:amd64

00:06:49

passed #219339
linux amd64
system:gcc:centos6:amd64

00:06:44

passed #219341
linux amd64
system:gcc:centos7:amd64

00:06:19

passed #219351
linux amd64
system:gcc:fedora29:amd64

00:06:17

passed #219363
linux amd64
system:gcc:jessie:amd64

00:06:20

passed #219347
linux amd64
system:gcc:sid:amd64

00:06:55

passed #219349
linux i386
system:gcc:sid:i386

00:06:49

passed #219362
linux amd64
system:gcc:stretch:amd64

00:06:24

passed #219353
linux amd64
system:gcc:xenial:amd64

00:06:48

passed #219360
linux amd64
system:pkcs11:sid:amd64

00:06:38

passed #219358
linux amd64
unit:asan:sid:amd64

00:00:56

passed #219359
linux amd64
unit:clang:stretch:amd64

00:00:44

passed #219356
linux amd64
unit:gcc:bionic:amd64

00:00:53

passed #219340
linux amd64
unit:gcc:centos6:amd64

00:00:49

passed #219342
linux amd64
unit:gcc:centos7:amd64

00:00:49

passed #219352
linux amd64
unit:gcc:fedora29:amd64

00:00:53

passed #219344
linux amd64
unit:gcc:jessie:amd64

00:00:32

passed #219348
linux amd64
unit:gcc:sid:amd64

00:00:49

passed #219350
linux i386
unit:gcc:sid:i386

00:00:48

passed #219346
linux amd64
unit:gcc:stretch:amd64

00:00:51

passed #219354
linux amd64
unit:gcc:xenial:amd64

00:00:48

passed #219361
linux amd64
unit:pkcs11:sid:amd64

00:00:49

failed #219343
linux amd64
system:gcc:jessie:amd64

00:06:55

failed #219345
linux amd64
system:gcc:stretch:amd64

00:06:50