Panel export: change IDs #841

[rozetko]

Closes #841

This PR changes panel importing process: when panel is being imported, IDs of analytic units / caches / segments / detection spans are changed to new ones

Disclaimer

Abbreviations in this PR:

• AU -> analytic unit
• AUC -> analytic unit cache
• S -> segment
• DS -> detection span

New import process:

• remove IDs from AU / AUC / S / DS while exporting
• import AU, database generates new IDs for them
• import AUC / S / DS with new analytic unit IDs

[rozetko]

@jonyrock-back Please, review it