I wrote a benchmark for `Binding`, such as:

    [Benchmark]
    public void BindName()
    {
        var binding = new Binding("Name", source: Source);
        Target.SetBinding(MyObject.NameProperty, binding);
    }

Attaching `dotnet-trace`, I found ~53% of the time was spent in
`MethodInfo.GetParameters()`:

    core.benchmarks!Microsoft.Maui.Benchmarks.BindingBenchmarker.BindName()
    ...
    microsoft.maui.controls!Microsoft.Maui.Controls.BindingExpression.SetupPart()
    System.Private.CoreLib.il!System.Reflection.RuntimeMethodInfo.GetParameters()

Reviewing the code, it was basically calling:

    System.Reflection.PropertyInfo.SetMethod.GetParameters()[0].ParameterType;

We can just call `PropertyInfo.PropertyType` instead, to avoid
allocating a `ParameterInfo[]` and indexing into it.

The results of this change in my benchmarks:

|             Method |     Mean |    Error |   StdDev |   Gen0 |   Gen1 | Allocated |
|------------------- |---------:|---------:|---------:|-------:|-------:|----------:|
|         --BindName | 18.82 us | 0.336 us | 0.471 us | 1.2817 | 1.2512 |  10.55 KB |
|         ++BindName | 18.80 us | 0.371 us | 0.555 us | 1.2512 | 1.2207 |  10.23 KB |
|        --BindChild | 27.47 us | 0.542 us | 0.827 us | 2.0142 | 1.9836 |  16.56 KB |
|        ++BindChild | 26.71 us | 0.516 us | 0.652 us | 1.9226 | 1.8921 |  15.94 KB |
| --BindChildIndexer | 58.39 us | 1.113 us | 1.143 us | 3.1738 | 3.1128 |  26.17 KB |
| ++BindChildIndexer | 58.00 us | 1.055 us | 1.295 us | 3.1128 | 3.0518 |  25.47 KB |

-- Before
++ After

This should help scrolling performance such as in dotnet#12130, where bindings
are updating while scrolling.