Update screenshots across the import docs

[catpetrychenko-rgb]

Pages that carry import screenshots:

Import from CSV/XLSX
Import Tests From TestRail
Import Tests From QTest
Import Tests From Zephyr
Import Tests From Qase
Import Tests From Testmo
Import Tests From QMetry
Import Tests From Allure TestOps
Import Tests From TestCaseLabs
Import Tests From XRay

https://docs.testomat.io/project/import-export/import/