feat(quote): add sgx report types

[definitelynobody]

This also removes quote types which will remain in steward for now.

Closes enarx-archive/sallyport#74

[rvolosatovs]

cargo doc warnings (within the added module):

warning: this URL is not a hyperlink
  --> src/report.rs:13:6
   |
13 | /// (https://download.01.org/intel-sgx/dcap-1.0/docs/SGX_ECDSA_QuoteGenReference_DCAP_API_Linux_1.0.pdf)
   |      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use an automatic link instead: `<https://download.01.org/intel-sgx/dcap-1.0/docs/SGX_ECDSA_QuoteGenReference_DCAP_API_Linux_1.0.pdf>`
   |
   = note: `#[warn(rustdoc::bare_urls)]` on by default
   = note: bare URLs are not automatically turned into clickable links

warning: this URL is not a hyperlink
  --> src/report.rs:18:6
   |
18 | /// (https://www.intel.com/content/www/us/en/architecture-and-technology/64-ia-32-architectures-software-developer-vol-3d-part-4-manual.ht...
   |      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use an automatic link instead: `<https://www.intel.com/content/www/us/en/architecture-and-technology/64-ia-32-architectures-software-developer-vol-3d-part-4-manual.html>`
   |
   = note: bare URLs are not automatically turned into clickable links

warning: this URL is not a hyperlink
  --> src/report.rs:93:6
   |
93 | /// (https://www.intel.com/content/www/us/en/architecture-and-technology/64-ia-32-architectures-software-developer-vol-3d-part-4-manual.ht...
   |      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use an automatic link instead: `<https://www.intel.com/content/www/us/en/architecture-and-technology/64-ia-32-architectures-software-developer-vol-3d-part-4-manual.html>`
   |
   = note: bare URLs are not automatically turned into clickable links

warning: `sgx` (lib doc) generated 7 warnings

I am not convinced about the added value of a separate report module. What do you think about either:
a. Having the Report, ReportBody, ReportError defined at the top-level? They may still reside in separate files/modules and be reexported, but IMO importing these as sgx::{Report, ReportBody, ReportError} is easier to use
b. Moving these to enclu, right next to where the EREPORT itself is defined
instead ?

[definitelynobody]

I think reexporting these makes some sense.

[rvolosatovs]

Can't comment on the validity of the actual struct definitions and parsing logic (maybe @jarkkojs should take a look?), but otherwise LGTM.