Feat/add sap zert pasting

[fheinke]

This pull request introduces a new feature that enables users to easily copy SAP-formatted time entry data to the clipboard, both for individual entries and for all aggregated weekly entries. It does so by adding copy-to-clipboard buttons and the necessary logic to format and copy the data in the correct SAP-compatible format. Additionally, it cleans up unused code and removes an obsolete component.

New SAP copy-to-clipboard functionality:

• Added a "Copy" button (with a clipboard icon) to each time entry row in the daily and weekly data grids, allowing users to copy the SAP-formatted entry for that row. [1] [2] [3] [4] [5]
• Added a "Copy All Entries for SAP" button above the aggregated time entries grid, allowing users to copy all weekly entries in SAP format at once. [1] [2]
• Implemented backend logic to format time entry data as required by SAP, including proper date formatting and localization for hours.

Codebase cleanup and refactoring:

• Removed the obsolete ProjectDataGridColumns.razor component, which is no longer used.
• Minor code cleanups, such as removing unnecessary comments and improving lookup performance for workdays and projects. [1] [2]

These changes improve user efficiency when transferring time tracking data to SAP and streamline the codebase by removing unused components.