[feature] Weaver needs to update to_XYZ_case helpers to match namespacing rules in semconv

[jsuereth]

See See open-telemetry/semantic-conventions#1118 for context

[lquerel]

I see two options to implement this:

1. Create a const_name filter that by default applies the namespacing rules and generates a SCREAMING_SNAKE_CASE ID. An optional case parameter will allow specifying another case converter after applying the namespacing rules.
2. Add an optional parameter to all existing case converters (i.e. pascal_case, screaming_snake_case. ...) to specify whether the conversion should take into account the namespacing rules. We need to find a short name for this flag.

[jsuereth]

I think 1. isn't practical because constants vary in definition. If const_name took the case type as an argument, then I think that'd be viable.

2. I like this, but it's also a bit of a footgun. I think it'd be more comfortable with semconv_const_name(case="Pascal")

[lquerel]

@jsuereth I'm confused :-)
So in conclusion, you prefer option 1, but you'd like to rename const_name to semconv_const_name or semconv_const. Right?