CLOUD-869 Enhance Jenkinsfile to skip builds for specified non-trigger files

[ptankov]

CHANGE DESCRIPTION

Problem:
Currently we start e2e test suite for every single PR without considering the changes in the PR. Ideally, we should run tests only if the changed files are related to source code or tests.

Solution:
The Jenkins pipeline reads the content of a file (e.g., .e2eignore), containing file names and/or folder names and globbings one name per line. It proceeds to run the tests only if there is a modified file outside of that list.

CHECKLIST

Jira

• Is the Jira ticket created and referenced properly?
• Does the Jira ticket have the proper statuses for documentation (Needs Doc) and QA (Needs QA)?
• Does the Jira ticket link to the proper milestone (Fix Version field)?

Tests

• Is an E2E test/test case added for the new feature/change?
• Are unit tests added where appropriate?
• Are OpenShift compare files changed for E2E tests (compare/*-oc.yml)?

Config/Logging/Testability

• Are all needed new/changed options added to default YAML files?
• Are all needed new/changed options added to the Helm Chart?
• Did we add proper logging messages for operator actions?
• Did we ensure compatibility with the previous version or cluster upgrade process?
• Does the change support oldest and newest supported PXC version?
• Does the change support oldest and newest supported Kubernetes version?

[JNKPercona]

Test name	Status
affinity-8-0	passed
auto-tuning-8-0	passed
cross-site-8-0	passed
custom-users-8-0	passed
demand-backup-cloud-8-0	passed
demand-backup-encrypted-with-tls-8-0	passed
demand-backup-8-0	passed
haproxy-5-7	passed
haproxy-8-0	passed
init-deploy-5-7	passed
init-deploy-8-0	passed
limits-8-0	passed
monitoring-2-0-8-0	passed
one-pod-5-7	passed
one-pod-8-0	passed
pitr-8-0	passed
pitr-gap-errors-8-0	passed
proxy-protocol-8-0	passed
proxysql-sidecar-res-limits-8-0	passed
pvc-resize-5-7	passed
pvc-resize-8-0	passed
recreate-8-0	passed
restore-to-encrypted-cluster-8-0	passed
scaling-proxysql-8-0	passed
scaling-8-0	passed
scheduled-backup-5-7	passed
scheduled-backup-8-0	passed
security-context-8-0	passed
smart-update1-8-0	passed
smart-update2-8-0	passed
storage-8-0	passed
tls-issue-cert-manager-ref-8-0	passed
tls-issue-cert-manager-8-0	passed
tls-issue-self-8-0	passed
upgrade-consistency-8-0	passed
upgrade-haproxy-5-7	passed
upgrade-haproxy-8-0	passed
upgrade-proxysql-5-7	passed
upgrade-proxysql-8-0	passed
users-5-7	passed
users-8-0	passed
validation-hook-8-0	passed
We run 42 out of 42

commit: be5cda2
image: perconalab/percona-xtradb-cluster-operator:PR-1901-be5cda23