Zephyr Migration Tool should check for invalid chars in issue summary

Zephyr Migration Tool should take in account invalid chars before issue creation/updated.

There are situations where the migration can fail, namely for older Jira issues. There is an old bug where users could create issues with line feed char in the summary.  (https://jira.atlassian.com/browse/JRASERVER-23494)

The bug was fixed but older issues can still have invalid chars, leading to failing migrations.