WIP: Fixing issue where Optional[List[Enum]] didn't work, among others

[smt5541]

🛠 Changes being made

Give examples of the changes you've made in this pull request. Include an itemized list if you can.

• Add list_disable_query_csv Parameter argument, and corresponding FPV_LIST_DISABLE_QUERY_CSV config option for setting the default value
  • FPV_LIST_DISABLE_QUERY_CSV defaults to False to maintain backwards compatibility
  • This allows users to choose whether they want comma-separated values to be separated into lists
  • Disabling CSV splitting allows those parameter types to accept list[dict] and accommodates the possibility of a str or StrEnum containing a ,
• Made generic type parsing (list, Union, Optional) recursive to enable support of list[Union[int, float]], Optional[list[int]], etc.
• Updated README to note that the default Parameter argument doesn't handle None as a valid default because it's treated as no default set

🧠 Rationale behind the change

Why did you choose to make these changes?

Does this pull request resolve any open issues?

Were there any trade-offs you had to consider?

🧪 Testing

• Have tests been added or updated for the changes introduced in this pull request?

• Are the changes backwards compatible?

If the changes aren't backwards compatible, what other options were explored?

✨ Quality check

• Are your changes free of any erroneous print statements, debuggers or other leftover code?

• Has the README been updated to reflect the changes introduced (if applicable)?

💬 Additional comments