[WIP] Update JA guide for Snowsight terminology (Worksheet -> Workspace/Notebook)

[sotanengel]

This PR is still a work in progress (WIP).
Content and wording are still being updated.

What changed

Updated site/sfguides/src/getting-started-with-snowflake-ja/getting-started-with-snowflake-ja.md to align with current Snowsight UI terminology and navigation.

• Replaced legacy ワークシート wording with ワークスペース / ノートブック where appropriate.
• Reworked the UI/navigation section to describe current left-nav items (Projects to Admin) with Japanese labels.
• Updated workflow steps to match current UI flow (role switching, catalog/database explorer navigation, notebook execution flow).
• Fixed and updated the Snowflake docs reference link for navigation.
• Applied wording updates across later sections to keep terminology consistent.

Notes

• This is not final yet; additional content cleanup and consistency checks are pending.
• Some sections still need refinement for screenshot/text alignment.

[snowflake-github-workato]

https://publish-p57963-e462098.adobeaemcloud.com/ja/developers/guides/getting-started-with-snowflake-ja-677ec89cb750f549cff963d893140bfc1b23c300

Note: The image uploads happen async, so they may not be uploaded yet if you click this quickly.. try again in a few minutes if so.

[snowflake-github-workato]

https://publish-p57963-e462098.adobeaemcloud.com/ja/developers/guides/getting-started-with-snowflake-ja-677ec89cb750f549cff963d893140bfc1b23c300

Note: The image uploads happen async, so they may not be uploaded yet if you click this quickly.. try again in a few minutes if so.

[snowflake-github-workato]

https://publish-p57963-e462098.adobeaemcloud.com/ja/developers/guides/getting-started-with-snowflake-ja-ad3c6c02be15f123363782949ac1b8405f4db17f

Note: The image uploads happen async, so they may not be uploaded yet if you click this quickly.. try again in a few minutes if so.

[snowflake-github-workato]

https://publish-p57963-e462098.adobeaemcloud.com/ja/developers/guides/getting-started-with-snowflake-ja-fa4c7408433987576eaac4c807d0da1bcaf27e37

Note: The image uploads happen async, so they may not be uploaded yet if you click this quickly.. try again in a few minutes if so.

[snowflake-github-workato]

https://publish-p57963-e462098.adobeaemcloud.com/ja/developers/guides/getting-started-with-snowflake-ja-b5024a3409bb40e82b523012c0552af2ef4b33ff

Note: The image uploads happen async, so they may not be uploaded yet if you click this quickly.. try again in a few minutes if so.

[snowflake-github-workato]

https://publish-p57963-e462098.adobeaemcloud.com/ja/developers/guides/getting-started-with-snowflake-ja-471b54f9dd2644e0ec05295045b935221d1c6563

Note: The image uploads happen async, so they may not be uploaded yet if you click this quickly.. try again in a few minutes if so.