datapack predicates don't check if their name is "valid"

all file and folder names in datapacks are limited to a-zA-z0-9 hovewer predicates don't check if their name follows this naming convention and instead of returning error invalid file name in the logs, they are listed when tab completing the /execute if predicate command and inaccessible couse they contain a space in their name

reproduction steps:

1 make a valid datapack predicate json file

2 copy that valid predicate file and rename it to contain spaces like "predicate - Copy"

3 reload the datapacks and see what predicate files are listed "usable" by /execute if predicate