Improve "too many parameters" error (#50539)
I'm still not satisfied with this but
```julia
ERROR: too many parameters for type AbstractTriangular
Stacktrace:
[1] top-level scope
@ REPL[3]:1
```
is slightly better than
```julia
ERROR: too many parameters for type
Stacktrace:
[1] top-level scope
@ REPL[3]:1
```
