want space before open-brace of enum

[fangism]

See first line:

Want:

typedef enum uint8_t {
  kFoo,
  kBar
} foo_t;

Got:

typedef enum uint8_t{
  kFoo,
  kBar
} foo_t;

Fix needs to add a case here:

https://github.com/google/verible/blob/0a331418dd3ba7cd8c98a8436f380638f0aeac91/verilog/formatting/token_annotator.cc#L336

by checking for context being immediately inside an enum.

[fangism]

b/164302106