Treat configuration-cache as an extracted entry

Instead of using a fallback strategy to locate a configuration-cache entry
based on the current job and git SHA, these entries are now keyed based on their
file content with the keys persisted in the primary Gradle User Home entry.

This removes the chance of having a configuration-cache entry restored that is
incompatible with the restored Gradle User Home state, and makes the logic easier
to understand.

This change involved a fairly major refactor, with the CacheEntryExtractor being
split out from the primary cache implementation, and adding a separate extractor
implementation for configuration-cache.

src/cache-utils.ts

@@ -46,6 +46,36 @@ export function hashStrings(values: string[]): string {
     return hash.digest('hex')
 }
 
+export async function restoreCache(
+    cachePath: string[],
+    cacheKey: string,
+    cacheRestoreKeys: string[] = []
+): Promise<cache.CacheEntry | undefined> {
+    try {
+        return await cache.restoreCache(cachePath, cacheKey, cacheRestoreKeys)
+    } catch (error) {
+        handleCacheFailure(error, `Failed to restore ${cacheKey}`)
+        return undefined
+    }
+}
+
+export async function saveCache(cachePath: string[], cacheKey: string): Promise<cache.CacheEntry | undefined> {
+    try {
+        return await cache.saveCache(cachePath, cacheKey)
+    } catch (error) {
+        handleCacheFailure(error, `Failed to save cache entry ${cacheKey}`)
+    }
+    return undefined
+}
+
+export function cacheDebug(message: string): void {
+    if (isCacheDebuggingEnabled()) {
+        core.info(message)
+    } else {
+        core.debug(message)
+    }
+}
+
 export function handleCacheFailure(error: unknown, message: string): void {
     if (error instanceof cache.ValidationError) {
         // Fail on cache validation errors