The pattern to construct `Application` was to use the `try_create`
method from the `C_OBJECT` macro. While being safe from an OOM
perspective, this method doesn't propagate errors from the constructor.
This patch make `Application` use the `C_OBJECT_ABSTRACT` and manually
define a `create` method that can bubble up errors from the
construction stage.
This commit also removes the ability to use `argc` and `argv` to
create an `Application`, only `Main`'s `Arguments` can be used.
From a user point of view, the patch renames `try_create` => `create`,
hence the huge number of modified files.
Both applications eventually reach LibGPU's loading of a dynamic library
(e.g. LibSoftGPU) which requires this pledge.
The pledge was always required, but went unchecked until 01318d8f9b.
Rip that bandaid off!
This does the following, in one big, awkward jump:
- Replace all uses of `set_main_widget<Foo>()` with the `try` version.
- Remove `set_main_widget<Foo>()`.
- Rename the `try` version to just be `set_main_widget` because it's now
the only one.
The majority of places that call `set_main_widget<Foo>()` are inside
constructors, so this unfortunately gives us a big batch of new
`release_value_but_fixme_should_propagate_errors()` calls.
