Fix for deploying the flexric in cloud-native env

Content

This MR includes the following modifications

improvements specifically targeting the cloud-native environment

1. improve cmakelist to optionally install the nearRT-RIC/agent/xapp executables and compile unit test folder 35ab5c30

2. add config for nearRT-RIC/agent/xapp 13ef2e88

3. add cu_du_id in global_e2_node_id_t to support agent in the dis-aggregated CU/DU and fix asn to enc/dec ran_type in E2 setup request 4a565187

4. add ran_type in the init_agent_api() 369d5d5c

Bugfix specifically targeting the cloud-native environment:

5. correct the sm shared lib (.so), flexric.conf file, and nearRT-RIC/agent/xapp executables to the proper path db190c3a 4e885dfe

6. correct the resending E42 setup request while there is no agent connected 49aa2caa (note: ric reply the e42 setup response while the expecting number of agent are connected)

7. add fflush() to print out the log 50ef3f37

Other improvements

8. add make uninstall to remove the installed executables db190c3a

9. add hello word xapp 3074ff83

10. update oai patch to support different ran_type and enable the calculation of RLC tx sdu waiting time aa419ab1

Other bugfix

11. fix path of the xapp in python to absolute path f4aa21c7

12. increase buffer size for writing the slice state in log.txt 7b180bee

13. increase buffer size for enc/dec E2/E42 setup reqeust to enable more than 16 agents/xapps are running at same time 8e273d1a

14. fix max number of parameter for runtime executable 57666759

Test plan

• tested in kubernetes/docker container environment with E2E methodology (apply oai.patch on the OAI branch: if5_ECPRI_rework(cfeae956) for testing CU/DU with Quectel UE)
• tested in physical env with E2E methodology (apply oai.patch on the OAI branch: develop(61e65959b0) for testing gNB with Quectel UE )
• tested unit test (test_ag_ric_xapp)
• tested three nodes test (nearRT-RIC, two emu_agent, xapp_monitor_all and xapp_slice)