feat: Add events to GazeDataFrame init

[dkrako]

Description

Add events keyword argument to GazeDataFrame initializer. For a start I would like to keep this rather simple.

552 must be merged first

Implemented changes

• [x] If events is None: create empty EventDataFrame
• [x] Else: create copy of passed EventDataFrame

Type of change

• [x] New feature (non-breaking change which adds functionality)

How Has This Been Tested?

• [x] Tested attributes after initialization for a few dataframe combinations

Checklist:

• [x] My code follows the style guidelines of this project
• [x] I have performed a self-review of my own code
• [x] I have commented my code, particularly in hard-to-understand areas
• [x] I have made corresponding changes to the documentation
• [x] My changes generate no new warnings
• [x] I have added tests that prove my fix is effective or that my feature works
• [x] New and existing unit tests pass locally with my changes
• [x] Any dependent changes have been merged and published in downstream modules
• [x] I have checked my code and corrected any misspellings

[codecov[bot]]

Codecov Report

Patch coverage: 100.00% and no project coverage change.

Comparison is base (097cbbb) 100.00% compared to head (01b8c03) 100.00%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #553 +/- ## ========================================= Coverage 100.00% 100.00% ========================================= Files 48 48 Lines 2139 2143 +4 Branches 521 522 +1 ========================================= + Hits 2139 2143 +4 ``` | [Files Changed](https://app.codecov.io/gh/aeye-lab/pymovements/pull/553?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=aeye-lab) | Coverage Δ | | |---|---|---| | [src/pymovements/gaze/gaze\_dataframe.py](https://app.codecov.io/gh/aeye-lab/pymovements/pull/553?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=aeye-lab#diff-c3JjL3B5bW92ZW1lbnRzL2dhemUvZ2F6ZV9kYXRhZnJhbWUucHk=) | `100.00% <100.00%> (ø)` | |

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