Allow std::string "name" arguments for ParmParse methods (#4695)

## Summary
The `ParmParse` constructor accepts argument `prefix == std::string`.
But once the object is created, methods on it require `char *` objects
for the `name` argument, leading to code like:
```
std::string prefix = "prefix";
std::string name = "name";
ParmParse pp(prefix);
pp.get(name.c_str(), input);
```

The proposed patch adds wrappers to allow arguments to `ParmParse`
methods `get`, `query`, etc, to allow the `name` argument to be a
`std::string`, so the `c_str()` is not needed and the interface is
consistent. It also fixes a few mismatches between comments and code.

## Additional background
Wrappers are provided for all methods except one. It was not possible to
add a `std::string` interface for the two-name version of `get`:
```
    void get (const char* new_name, const char* old_name, T& ref)
```
because with `string` values for the first two arguments and an `int`
value for the third, this creates an ambiguity with the standard `get`:
```    
     void get (const std::string&  name,
              std::string& ref,
              int          ival = FIRST)
```
For this reason, a wrapper is not provided for the two-name version of
`get`.
Currently the only thing that disambiguates this template from the
standard `get` is that in the two-name version both names are `char*`
and in the template the second argument `ref` is `std::string`, allowing
the first argument to be `string` breaks this. This is an unforunate
feature of the API design.
Furthermore I believe this function is somewhat obscure and it should
possibly be deprecated or renamed to `get_with_fallback` or `get2` or
similar.


## Checklist

The proposed changes:
- [ ] fix a bug or incorrect behavior in AMReX
- [x] add new capabilities to AMReX
- [ ] changes answers in the test suite to more than roundoff level
- [ ] are likely to significantly affect the results of downstream AMReX
users
- [ ] include documentation in the code and/or rst files, if appropriate

---------

Co-authored-by: Charles G Waldman <[email protected]>
Co-authored-by: Weiqun Zhang <[email protected]>

Author: 3 people