Enhance CEL support in runtime event log fetching

[Ruoyu-y]

What would you like to be added?

Support CEL in all three languages in vmsdk implementation.
Currently, we only support the CEL standard in our python implementation and limited to the TLV encoding. For next steps, we need to provide full support for all encodings (TLV, CBOR and native JSON).

Why is this needed?

Canonical Event Log(CEL) located at https://trustedcomputinggroup.org/wp-content/uploads/TCG_IWG_CEL_v1_r0p30_13feb2021.pdf is the recent standard from TCG that can encapsulate native Event Log Records from various sources.
This specification also provides a simple Type-Length-Value (TLV) encoding layer and a Concise Binary Object
Representation (CBOR) encoding layer. This specification covers TLV and CBOR encapsulation of some content
layers, including CEL Management, PCCLIENT [2] and IMA [5] content. While a content layer implementation may choose to create an exact binary mapping to this information model as its native Event Log Record, other
implementations may choose to bind this information model to other formats, such as TLV or CBOR.
This specification is also an important standard for runtime measurement, as it covers the scope of IMA which is one of the fundamental technologies that leverage by the CC API.