Improve e2e test readeability

Test test should be easy to read and requires a lot of helper methods in order to avoid duplicate code.

This is a quite readable test:

https://github.com/cheminfo/nmrium/blob/4f8660b06311855e50b7f5462d66744331fa710f/test-e2e/panels/integral.test.ts#L70-L90

The following test is not optimal. The following code:

https://github.com/cheminfo/nmrium/blob/4f8660b06311855e50b7f5462d66744331fa710f/test-e2e/core/import.test.ts#L95-L98

Could be written:

`await checNumberOfRangesInPanel(nmrium, 6)`

Helper functions should be often shared between testcase as well.

Start by comparing the readable example in test-e2e/panels/integral.test.ts and the target code in test-e2e/core/import.test.ts at the referenced lines. Identify helper functions that can be shared between test cases and improve the target test's readability without duplicating them. Done means the affected e2e tests are easier to read and repeated helper logic is shared.

Written by the indexing model from the issue text.