Handle non-clock entries in logbook

[jamesnvc]

Address #111 and (hopefully) #108 (edit: and #110)

Currently, this lacks the ability to edit comments/non-clock lines in the logbook, but will preserve them.

[munen]

Big thanks for the quick PR! 🙏

During testing, I found a regression. When there's comments in the :LOGBOOK: drawer, the only action is "clock out", never "clock in". That's because the hasActiveClock logic in Header/index.js only looks for missing end elements whereas now it should probably also look for raw elements.

[munen]

@jamesnvc Super job - PR looking sharp as always! 🙏

Gladly pulling it in without changes^^

[munen]

I updated the changelog with attribution: c9375f8

Great job on potentially closing three issues in one go! 🚀