Rust__output tbe files

[DeviPriya-Kolla]

Description:
This issue involves implementing the functionality to export Rust-native data structures back into the TBE file format, ensuring that the output adheres to the TBE standard (i.e., data can be read, modified, and saved without loss or structural changes).

Developer Notes:

• Implement a core function, exportToTBEFile, to handle converting Rust data structures into the TBE format, ensuring that each data section (e.g., metadata, TBL, ATT) is formatted correctly and enclosed within the proper delimiters (BGN and EOT).
• Utilize appropriate Rust data structures such as HashMap for metadata, Vec for lists of data, and possibly custom structs to represent the various TBE sections
• Use Rust's standard library I/O features (such as BufWriter and File) to handle file output efficiently.

Acceptance Criteria:

• Rust Data Export to TBE Format
• Inclusion of BGN and EOT Delimiters
• Needs to preserve metadata
  • Global TBL metadata
  • Metadata for "sites" section
• Ensures round-trip compatibility
• error handling checks
  • give clear error messages
  • implement checks for missing critical data before exporting