fix(readRawBody): handle body as object

[igorjacauna]

• Closes [nuxt] [request error] [unhandled] [500] The first argument must be of type string or an instance of Buffer, ArrayBuffer, or Array or an Array-like Object. Received an instance of Promise #381
• Related to 19d133d

Based in on this where seems unenv already parsed the body to Object and when try to create a Buffer from it, in nitro Firebase preset, throw a error mentioned here

TypeError [ERR_INVALID_ARG_TYPE]: The first argument must be of type string or an instance of Buffer, ArrayBuffer, or Array or an Array-like Object. Received an instance of Object

This change check if body is a Object and converts to string before create a Buffer from it

[codecov]

Codecov Report

Merging #403 (3703b63) into main (6fd36cf) will increase coverage by 0.05%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main     #403      +/-   ##
==========================================
+ Coverage   76.21%   76.26%   +0.05%     
==========================================
  Files          26       26              
  Lines        2438     2444       +6     
  Branches      339      341       +2     
==========================================
+ Hits         1858     1864       +6     
  Misses        580      580              

Impacted Files	Coverage Δ
src/utils/body.ts	93.12% <100.00%> (+0.32%)	⬆️

[pi0]

Thanks LGTM!

BTW this is something we probably have to resolve in nitro presets to make sure provided body is a stream...