Suggest `PluginFoo` -> `FooPlugin` rename in `unconventional_naming`

[BD103]

struct PluginFoo;

unconventional_plugin currently suggests it be renamed to PluginFooPlugin. It should instead suggest FooPlugin. This can be implemented in TraitSuggestion::name_suggestion():

bevy_cli/bevy_lint/src/lints/style/unconventional_naming.rs

Line 222 in e85154b

TraitConvention::Plugin => format!("{struct_name}{}", self.suffix()),