Fix issue with non-default dayborder in part 5

[vincentvanhees]

This PR fixes #1006
The problem was that g.part5.definedays.R() did not correctly expand object nightsi. @jhmigueles this relates to the qwindow implementation in part 5 you did, so it would be good if you could check that this does not break any functionality you intended.

Further, in this PR includes minor fixes:

• Correct assumption by g.part5.definedays.R() that "00:00:00" is always the start of a MM segment.
• I removed some of the cat() statements that are not informative for the user, also I opened a new issue Make code less verbose and review need for cat() statements #1007 to do a more systematic review of this in the new year
• I changed the ordering of the part 5 report rows, because for the segment report it was not doing the ordering correct.

Checklist before merging:

• Existing tests still work (check by running the test suite, e.g. from RStudio).
• Added tests (if you added functionality) or fixed existing test (if you fixed a bug).
• Updated or expanded the documentation.
• Updated release notes in inst/NEWS.Rd with a user-readable summary. Please, include references to relevant issues or PR discussions.
• Added your name to the contributors lists in the DESCRIPTION file, if you think you made a significant contribution.

[jhmigueles]

Everything works well after several tests with segments and different dayborders.

In the tests I observed a minor issue which triggers an error when ID cannot be matched with the IDs available in the activity log. I have done a commit that addresses this issue.