common svp (Secure Video Path) changes added and new gst-svp-ext interface used to move the SoC changes from Mediasession

[afranc083]

• Common SVP (Secure Video Path) feature is supported
• New gst-svp-ext interface is used to move the SoC specific changes from Mediasession. reference https://code.rdkcentral.com/r/plugins/gitiles/rdk/components/generic/gst_svp_ext
• Different DRM Decrypt() APIs are supported based on AES CBC/CTR. like Drm_Reader_DecryptOpaque() and Drm_Reader_DecryptMultipleOpaque()
• CMake changes are done to ensure the Compilation with Realtek & Amlogic platform
• We are aligned with Common rdk-adapter. reference: https://github.com/rdkcentral/ThunderClientLibraries/blob/master/Source/ocdm/adapter/rdk/open_cdm_adapter.cpp

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