[API] Add improved slot locator functions (#716)

- Returns object with slot, index, and pos
- Locate-by-type returns object with slot & index
- Uses standard `undefined` return for concise chaining & validation
- Free 10x perf increase over getConnectionPos (used basic random data
to test, out of curiosity)

src/strings.ts

@@ -1,3 +1,5 @@
+import type { ISlotType } from "./litegraph"
+
 /**
  * Uses the standard String() function to coerce to string, unless the value is null or undefined - then null.
  * @param value The value to convert
@@ -15,3 +17,7 @@ export function stringOrNull(value: unknown): string | null {
 export function stringOrEmpty(value: unknown): string {
   return value == null ? "" : String(value)
 }
+
+export function parseSlotTypes(type: ISlotType): string[] {
+  return type == "" || type == "0" ? ["*"] : String(type).toLowerCase().split(",")
+}