Naming of SET APIs in C.

[housengw]

related issues / PRs:
reactor-c #68
lingua-franca #1097
lingua-franca #1103

The SET APIs in the c target are being updated and this is a good opportunity to update their names as well.
Since the visibility of the SET APIs are limited to the body of a reaction and are C macros, the user cannot use anything with the same name as the SET APIs inside a reaction.

There are currently 3 alternatives that is decided between:

i. Use uppercase (ex. SET, SET_ARRAY, SET_TOKEN)
Pros: this is the naming scheme currently used.
Cons: SET is a less common name than set, but still quite common.

ii. Use lowercase (ex. set, set_array, set_token)
Pros: easiest to type.
Cons: set is a common name in C. So this limits the user from using anything named set in the body of a reaction.

iii. Use lf_ prepended (ex. lf_set, lf_set_array, lf_set_token)
Pros: least likely to have name conflicts. Align well with the conventional naming style in C.
Cons: names are more verbose compared to (i) and (ii).
If we prefix SET APIs with lf_, we also want to prefix schedule functions with lf_

Please cast your vote below! If you have other naming recommendations, feel free to add them too.

Additional Suggestions that came up during LF Meeting (2022-04-20):

1. keep uppercase SET but still limit scope to body of reaction.
2. make the naming of SET APIs configurable as a target property.
3. If we change the SET APIs naming, we could add a target property like legacy-support and include files to support older versions of APIs. Include that file in 0.2.0 by default and not by default in 0.3.0

Action Items:

• come up with a list of other APIs to rename:
  • get_physical_time and the like
  • schedule and the like