[FEATURE] Create external accounts module to display gateway/consumer accounts

[TASK] Add latest data fields to payment submodule

[TASK] Update tests with external transaction model changes
[TASK] Update router and add routes/links to accounts section
[TASK] Improve validation mixin

[TASK] Ignore validation for non-required empty/undefined/null attributes

[FIX] Fail isNumber validation if value is NaN

[TASK] Create separate validation method for single attribute/value

[FIX] Perform require validations on correct attributes

[TASK] Prevent attribute validation if no rules are present
[FEATURE] Create bank accounts for gateways and customers
[FEATURE] Send inbound payment to gateway
[TASK] Code cleanup
[TASK] Create glyphicon chevron shared module to toggle between up/down icons
[TASK] Remove highlighting of new payments in preparation of pagination