Add tooltips to all labels - not just to the widgets themselves

[p-j-smith]

Part of #266

[codecov-commenter]

Codecov Report

Patch coverage: 100.00% and project coverage change: +0.05% :tada:

Comparison is base (bc6e1da) 85.68% compared to head (9541da3) 85.73%.

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Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #360 +/- ## ========================================== + Coverage 85.68% 85.73% +0.05% ========================================== Files 30 30 Lines 2144 2152 +8 Branches 394 394 ========================================== + Hits 1837 1845 +8 Misses 226 226 Partials 81 81 ``` | [Files Changed](https://app.codecov.io/gh/quantumjot/btrack/pull/360?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Alan+R+Lowe) | Coverage Δ | | |---|---|---| | [btrack/napari/widgets/create\_ui.py](https://app.codecov.io/gh/quantumjot/btrack/pull/360?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Alan+R+Lowe#diff-YnRyYWNrL25hcGFyaS93aWRnZXRzL2NyZWF0ZV91aS5weQ==) | `98.87% <100.00%> (+0.11%)` | :arrow_up: |

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[deprecated-napari-hub-preview-bot[bot]]

Preview page for your plugin is ready here: https://preview.napari-hub.org/quantumjot/btrack/360 Updated: 2023-08-03T14:28:52.543350