feat(nodes): move all invocation metadata (type, title, tags, category) to decorator

All invocation metadata (type, title, tags and category) are now defined in decorators.

The decorators add the `type: Literal["invocation_type"]: "invocation_type"` field to the invocation.

Category is a new invocation metadata, but it is not used by the frontend just yet.

- `@invocation()` decorator for invocations

```py
@invocation(
    "sdxl_compel_prompt",
    title="SDXL Prompt",
    tags=["sdxl", "compel", "prompt"],
    category="conditioning",
)
class SDXLCompelPromptInvocation(BaseInvocation, SDXLPromptInvocationBase):
    ...
```

- `@invocation_output()` decorator for invocation outputs

```py
@invocation_output("clip_skip_output")
class ClipSkipInvocationOutput(BaseInvocationOutput):
    ...
```

- update invocation docs
- add category to decorator
- regen frontend types

invokeai/app/invocations/prompt.py

@@ -1,5 +1,5 @@
 from os.path import exists
-from typing import Literal, Optional, Union
+from typing import Optional, Union
 
 import numpy as np
 from dynamicprompts.generators import CombinatorialPromptGenerator, RandomPromptGenerator
@@ -7,17 +7,13 @@ from pydantic import validator
 
 from invokeai.app.invocations.primitives import StringCollectionOutput
 
-from .baseinvocation import BaseInvocation, InputField, InvocationContext, UIComponent, tags, title
+from .baseinvocation import BaseInvocation, InputField, InvocationContext, UIComponent, invocation
 
 
-@title("Dynamic Prompt")
-@tags("prompt", "collection")
+@invocation("dynamic_prompt", title="Dynamic Prompt", tags=["prompt", "collection"], category="prompt")
 class DynamicPromptInvocation(BaseInvocation):
     """Parses a prompt using adieyal/dynamicprompts' random or combinatorial generator"""
 
-    type: Literal["dynamic_prompt"] = "dynamic_prompt"
-
-    # Inputs
     prompt: str = InputField(description="The prompt to parse with dynamicprompts", ui_component=UIComponent.Textarea)
     max_prompts: int = InputField(default=1, description="The number of prompts to generate")
     combinatorial: bool = InputField(default=False, description="Whether to use the combinatorial generator")
@@ -33,14 +29,10 @@ class DynamicPromptInvocation(BaseInvocation):
         return StringCollectionOutput(collection=prompts)
 
 
-@title("Prompts from File")
-@tags("prompt", "file")
+@invocation("prompt_from_file", title="Prompts from File", tags=["prompt", "file"], category="prompt")
 class PromptsFromFileInvocation(BaseInvocation):
     """Loads prompts from a text file"""
 
-    type: Literal["prompt_from_file"] = "prompt_from_file"
-
-    # Inputs
     file_path: str = InputField(description="Path to prompt text file")
     pre_prompt: Optional[str] = InputField(
         default=None, description="String to prepend to each prompt", ui_component=UIComponent.Textarea