Use simpler schema names for expressions

**Is your feature request related to a problem or challenge? Please describe what you are trying to do.**

We currently use overly verbose schema names for expressions. Here is an example comparing scalar function names between Postgres and DataFusion.

## Postgres

```
postgres=# select concat(a, 'utf8', true, false, null, 1, 0.2) from t;select concat(a, 'utf8', true, false, null, 1, 0.2) from t;
concat
-------------
...
```

## DataFusion

```
❯ select concat(a, 'utf8', true, false, null, 1, 0.2) from t;
+----------------------------------------------------------------------------------+
| concat(t.a,Utf8("utf8"),Boolean(true),Boolean(false),NULL,Int64(1),Float64(0.2)) |
+----------------------------------------------------------------------------------+
...
```

**Describe the solution you'd like**
Use simple names in schema - use the function name in this example and do not add the parameters.

**Describe alternatives you've considered**
None

**Additional context**
None

Reproduce the reported concat query in DataFusion and trace how expression schemas are generated and displayed. The work is done when the schema uses the function name without its argument details, while the query result remains correct.

Written by the indexing model from the issue text.