[web] Use hook instead of connect and HOC in RegisterModal
[web] Use hook instead of connect and HOC in RegisterModal

Test Plan: Flow

Reviewers: palys-swm, ashoat

Reviewed By: ashoat

Subscribers: ashoat, KatPo, zrebcu411, Adrian, atul, karol-bisztyga

Differential Revision: https://phabricator.ashoat.com/D774

Ashoat/squadcal,Ashoat/squadcal,Ashoat/squadcal,Ashoat/squadcal,Ashoat/squadcal,Ashoat/squadcal,Ashoat/squadcal