[I18N] Update translation terms from Transifex

addons/account/i18n/bg.po

addons/account/i18n/cs.po

addons/account/i18n/fr.po

addons/account/i18n/pl.po

addons/account/i18n/ro.po

addons/account_asset/i18n/bg.po

addons/account_asset/i18n/pl.po

addons/account_bank_statement_import/i18n/pl.po

addons/account_tax_cash_basis/i18n/pl.po

addons/account_test/i18n/ro.po

addons/analytic/i18n/bg.po

addons/analytic/i18n/ro.po

addons/auth_oauth/i18n/bg.po

addons/auth_signup/i18n/bg.po

addons/base_action_rule/i18n/bg.po

addons/base_gengo/i18n/bg.po

addons/base_gengo/i18n/cs.po

addons/base_import/i18n/cs.po

addons/calendar/i18n/bg.po

addons/calendar/i18n/vi.po