use current year for bar chart

[HenrikeW]

Related issue(s) and PR(s)

This PR closes #594

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Other

List of changes made

instead of looking 12 months back from today to get the range for the time log overview, we set January 1st in the current year as a start date for the data fetch.

Screenshot of the fix

Testing

-go to the report page and check the API requests in the dev tools

• The requests fetching time entries for a given time frame should have 2022-01-01 as start date and today's date as end date. It should look something like this:
  

Further comments

Definition of Done checklist

• I have made an effort making the commit history understandable
• I have performed a self-review of my own code and commented any hard-to-understand areas
• Tests and lint/format validations are passing
• My changes generate no new warnings