[backend] add paypal textbox and domenii de activitate selectbox for NGO

[johnsmithm]

for selectbox use these predifined options

https://www.figma.com/file/Fm1mdnskOPnJCX1AWgpR3U/Ajut.md_Web-Design_UI?node-id=266%3A2377

[vitaliel]

@johnsmithm below activity categories? With icons?

[johnsmithm]

yes

[vitaliel]

I added activity_type(domenii de activitate) as select in #34

where paypal email should be entered?