Eliminate multiple seed phrases

[jojobyte]

Upon initial implementation, https://github.com/dashhive/DashWallet.js lacked the ability to add multiple addresses to one wallet (seed phrase) but should have that ability now.

We should eliminate the one-to-one wallet-address pairing and instead allow generating new public addresses within a single wallet (seed phrase), while maintaining the ability to signup for CrowdNode with each public address.

[jojobyte]

• https://youtu.be/dNI6SAB9GMY
• https://youtu.be/CIZoBbUragA