Filter time entries by description

[zmoog]

Motivation

I want to filter time entries by description; sometimes you want to only see entries matching a substring, keeping the total amount of time.

Here's an example:

$ tgl entries --description SDH list --start-date 2023-03-27 

  description                                       Duration
 ────────────────────────────────────────────────────────────
  SDH 3229                                          6:13
  SDH 3237                                          4:52
  SDH 3069                                          4:03
  SDH 3149                                          3:27
  SDH 3256                                          2:22
  SDH 3247                                          2:18
  SDH 3140                                          1:07
  SDH 3253                                          0:56
 ────────────────────────────────────────────────────────────
  Total                                             25:10

Change description

Add a simple --description option to filter the time entries to the entries command group, so it's available to all time entries related commands.

The API endpoint does not offer filtering capabilities, to we are performing the filtering on the client side.

Additional Notes

Closes: #16

Reviewer checklist

• PR address a single concern.
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• Changes will be merged in main.
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