Enhances most of the messages for the end users.
Two major changes can be noticed:
1. In most cases no class name will be written in the message; it
prevents users that potentially have no access to the codebase to
get a useless/unclear information.
2. The input values are now properly formatted; for instance a string
value will now be written directly instead of the type `string`;
arrays are also handled with the array shape format, for instance:
`array{foo: 'some string'}`.
Previously, the method `TreeMapper::map` would allow mapping only to an
object. It is now possible to map to any type handled by the library.
It is for instance possible to map to an array of objects:
```php
$objects = (new \CuyZ\Valinor\MapperBuilder())->mapper()->map(
'array<' . SomeClass::class . '>',
[/* … */]
);
```
For simple use-cases, an array shape can be used:
```php
$array = (new \CuyZ\Valinor\MapperBuilder())->mapper()->map(
'array{foo: string, bar: int}',
[/* … */]
);
echo strtolower($array['foo']);
echo $array['bar'] * 2;
```
This new feature changes the possible behaviour of the mapper, meaning
static analysis tools need help to understand the types correctly. An
extension for PHPStan and a plugin for Psalm are now provided and can be
included in a project to automatically increase the type coverage.
