[Oracle/Client] Report card database download progress (#7253)

* [Oracle/Client] Report card database download progress

Card database updates ran invisibly: MTGJSON parsing spun an indeterminate
bar on the UI thread and the set import blocked the window, while the
onboarding wizard spawned `oracle -b` with no progress to show at all.

- Add byte-level scan progress to `RawJson::scanSetRanges` via an optional
  callback, throttled to ~100 reports per scan.
- Emit `OracleImporter::dataReadProgress` during the scan and import sets on a
  worker thread, driving the wizard's progress bar per set.
- With `-b`, write machine-readable `PROGRESS <stage> <done> <total>` lines to
  stdout for the download/scan/import stages; stderr keeps the log output.
- Parse the oracle stdout in `MainWindow` and forward it to the onboarding
  wizard, giving the card database step a determinate bar with stage-specific
  status text.
- Guard the async workers against the wizard being closed mid-run.
- Add Google Test coverage for scan progress reporting.

* [Oracle/Client] Harden oracle progress workers and quit prompt

Address review feedback on the download-progress change: decompress and read
sets files off the UI thread, cancel the load/import workers before the
wizard can tear down the importer, and show an 'Extracting file...' status
plus a clean 100% tail so the poll never looks stuck. Quitting Cockatrice
while a card database update runs now asks for confirmation.

* Show 100% for 500ms on complete.

* Disable buttons on set import until done.

* Clean up progress bar.

* Drop wrapper around lambda

---------

Co-authored-by: Lukas Brübach <Bruebach.Lukas@bdosecurity.de>

oracle/src/raw_json_scanner.h

@@ -4,6 +4,7 @@
 #include <QByteArray>
 #include <QList>
 #include <QString>
+#include <functional>
 
 namespace RawJson
 {
@@ -42,6 +43,13 @@ struct ScanError
     QString message;
 };
 
+/**
+ * @brief Optional progress callback receiving @c (bytesRead, totalBytes) while
+ * the document is walked. Invoked from the scanning thread; the caller decides
+ * how the throttled offsets are relayed to a GUI event loop.
+ */
+using ScanProgressCallback = std::function<void(qsizetype bytesRead, qsizetype totalBytes)>;
+
 /**
  * @brief Scans a full MTGJSON document without materializing the JSON tree.
  *
@@ -67,9 +75,14 @@ struct ScanError
  * @param error Out parameter. Set to an error ScanError when the document
  *              cannot be parsed, otherwise left empty. Passing a null
  *              pointer disables error reporting.
+ * @param progress Optional progress callback. When non-empty it is invoked as
+ *                 the scanner advances through the document, throttled to a
+ *                 tiny fraction of the total size.
  * @return The detected per-set ranges, or an empty list on failure.
  */
-QList<SetRange> scanSetRanges(const QByteArray &json, ScanError *error = nullptr);
+QList<SetRange> scanSetRanges(const QByteArray &json,
+                              ScanError *error = nullptr,
+                              const ScanProgressCallback &progress = ScanProgressCallback());
 
 } // namespace RawJson