Duplicating invoice does not correctly fill tax rate

[atymic]

Repro steps:

1. Check invoice you are duplicating, note tax rate selected and applies
2. Duplicate invoice, see shown cloned version copies most things, but missed applying the tax rate

Mis invoiced a couple of times due to this, as the old flutter UI correctly clones tax rates.

Thanks :)

[turbo124]

@Civolilah we'll want to ensure the line items / taxes etc are brought over on clone

[atymic]

Line items work, it's just the tax rate doesn't seem to apply.

[atymic]

Thanks 🙏