Add OranO2Keywords class with methods for SMO service account,
SMO secret, app config, certificates, and helm override.
Add generate_file_from_template to FileKeywords for non-YAML
template rendering and upload.
Fix kubectl_file_delete_keywords to handle missing files when
ignore_not_found=True.
Replace envsubst-based approach with Jinja2 templates for all
O-RAN O2 configuration files.
Test Plan:
PASS: Tested on AIO-SX system
Change-Id: I417954ca8eae8c541ff87ed0f5317ba82cbb917d
Signed-off-by: sgoapshe <SanketS.Gopashetty@windriver.com>