feat: add userdata support

[ethanholz]

This pull request enhances the DevBox CLI and launch script with improved option handling, user data script support, and overall code consistency. The most significant update is the addition of a --userdata-file option to allow passing a cloud-init script when launching a new EC2 instance. Additionally, the code has been refactored for better readability and consistency, especially in argument parsing and dictionary key usage.

User data script support:

• Added a --userdata-file option to the launch CLI command and the launch_programmatic interface, allowing users to specify a cloud-init format script to be passed as instance user data. This includes a new read_userdata_file helper and the necessary wiring in both cli.py and launch.py to read and pass the file contents. [1] [2] [3] [4] [5]

CLI and argument parsing improvements:

• Standardized the use of double quotes for Click argument and option names, and restructured multi-line option definitions for clarity in cli.py. [1] [2] [3] [4]
• Updated the argument parser in launch.py to use more readable multi-line calls and consistent double quotes.

General code consistency and cleanup:

• Improved dictionary key usage throughout the CLI to use double quotes for consistency. [1] [2] [3] [4]
• Minor improvements to error handling, code formatting, and documentation for better maintainability and clarity. [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11]

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This PR chooses not to store userdata in AWS because you most likely will not rerun userdata on every launch since most of the time it is used to populate the home directory. This enables you to also use other scripts on launching the new instance if needed.

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Pull request overview

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[ethanholz]

@dwhswenson this is ready for review whenever you are!

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 99.75%. Comparing base (bbeadcd) to head (acd1568).
⚠️ Report is 5 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #10      +/-   ##
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+ Coverage   99.73%   99.75%   +0.01%     
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  Files          13       13              
  Lines        2690     2818     +128     
==========================================
+ Hits         2683     2811     +128     
  Misses          7        7              

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[dwhswenson]

Finally got that merge done! LGTM