Hi, thank you for creating such a great framework!
I have a feature request which I think I can contribute, but let me check if you are interested in supporting it.

### Preflight Checklist
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* [x] I have read the [Contributing Guidelines](https://github.com/electron/electron/blob/master/CONTRIBUTING.md) for this project.
* [x] I agree to follow the [Code of Conduct](https://github.com/electron/electron/blob/master/CODE_OF_CONDUCT.md) that this project adheres to.
* [x] I have searched the issue tracker for a feature request that matches the one I want to file, without success.

### Problem Description
The builtin spellchecker has been supported in https://github.com/electron/electron/pull/20692.
But it does not allow us to check spells programmatically, like [node-spellchecker](https://github.com/felixrieseberg/node-spellchecker)'s `isMisspelled` method.
Chrome's spellcheck_platform provides [CheckSpelling](https://chromium.googlesource.com/chromium/src/+/46ee392970e491fb9ee2523348e23222b40d5119/components/spellcheck/browser/spellcheck_platform.h#60) to do that exactly.

### Proposed Solution
Add a method to call `spellcheck_platform::CheckSpelling` like so:

```cc
#if BUILDFLAG(USE_BROWSER_SPELLCHECKER)
bool Session::CheckSpelling(const std::string& word) {
  if (spellcheck::UseBrowserSpellChecker()) {
    return spellcheck_platform::CheckSpelling(base::UTF8ToUTF16(word), 0);
  }
  return true;
}
#endif
```

in `shell/browser/api/atom_api_session.cc`.

It's simple and won't affect other features.

### Alternatives Considered
I don't know.

### Additional Information
None

Thanks!
shell/renderer/api/electron_api_web_frame.cc
#include "content/public/renderer/render_view.h"
#include "services/service_manager/public/cpp/interface_provider.h"
#include "shell/common/api/api.mojom.h"
#include "shell/common/gin_converters/blink_converter.h"
#include "shell/common/gin_converters/callback_converter.h"
#include "shell/common/gin_helper/dictionary.h"
#include "shell/common/gin_helper/error_thrower.h"
#include "shell/common/gin_helper/promise.h"
#include "shell/common/node_includes.h"
#include "shell/common/options_switches.h"
#include "shell/renderer/api/electron_api_spell_check_client.h"
#include "third_party/blink/public/common/page/page_zoom.h"
#include "third_party/blink/public/common/web_cache/web_cache_resource_type_stats.h"
#include "third_party/blink/public/platform/web_cache.h"
#include "third_party/blink/public/platform/web_isolated_world_info.h"
#include "third_party/blink/public/web/web_custom_element.h"
#include "third_party/blink/public/web/web_document.h"
#include "third_party/blink/public/web/web_element.h"
#include "third_party/blink/public/web/web_frame_widget.h"
#include "third_party/blink/public/web/web_input_method_controller.h"
#include "third_party/blink/public/web/web_local_frame.h"
#include "third_party/blink/public/web/web_script_execution_callback.h"
#include "third_party/blink/public/web/web_script_source.h"
#include "third_party/blink/public/web/web_view.h"
#include "ui/base/ime/ime_text_span.h"
#include "url/url_util.h"
namespace gin {
template <>
struct Converter<blink::WebLocalFrame::ScriptExecutionType> {
  static bool FromV8(v8::Isolate* isolate,