fix(chromia): upgrade ft4 and postchain to 2.0.2 to fix type error in balanceOf (#522)

* fix(chromia): upgrade ft4 and postchain to 2.0.2 to fix type error in balanceOf

* chore(changeset): bump wallet-chromia for dependency fix (ft4/postchain 2.0.2)

* chore: update example and workspace files for Chromia 2.0.2 upgrade

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Co-authored-by: Philip Hilm <philip.hilm@chromaway.com>