v3.0.0 of littlefish_payments_softpos_halo_dot

A littlefish package that utilises the haloDot payment gateway Changelog excerpt: > Note: This release has breaking changes. - FIX(halo-dot): update halo_sdk_flutter_plugin to version 1.0.7 and littlefish_payments to version 8.0.1; remove unused dependencies. - FIX(halo-dot): invoke callback with empty token on JWT fetch failure. - FEAT(halo-dot): update littlefish_payments_pos_fnb to v8.0.3 with post-processing command support and new FNB print formatter. - FEAT(halo-dot): LA-368 implement card-present refund flow. - BREAKING FEAT(halo-dot): remove [...]