Mark e2e testsuite obsolete and disable it before removal.

[pmacik]

Motivation

This is the first step of removing the e2e test suite in favour of acceptance tests (https://issues.redhat.com/browse/APPSVC-648)

Changes

This PR disables the e2e tests by default unless ENABLE_OBSOLETE_E2E is set to true.
A warning like the following is shown instead:

$ make test-e2e
!WARNING: e2e tests are obsolete and will be removed soon in favour of acceptance tests,
!          so they are disabled by default. If you need to run it anyway, set ENABLE_OBSOLETE_E2E=true in the environment.
make: Nothing to be done for 'test-e2e'.

Testing

make test-e2e

[pmacik]

/retest

[pedjak]

/lgtm
/approve

[pedjak]

As CI shows, e2e-log-parser.sh file should be also made no-op.

[pedjak]

/retest

[pedjak]

/lgtm
/approve

[openshift-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: pedjak

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