[ 7.0.0] `template_engine:` basic support

[iromeo]

1) Do not highlight template_engine as unrecognized section 2) Inspections:

• Only one argument expected after template_engine
• Keywords arguments not supported after template_engine
• Do not warn about unused log section if rule wiht template_engine
• template_engine is execution section, so could not be with run/shell/notebook/script
• template_engine should be last in the rule
• Completion for "yte", "jinja2" in template_engine string argument

• Inspection that warns when template= keyword argument is required in section with template_engine

  Snakemake feature introduced in:

• 7.0.0 - template rendering integration (yte and jinja2) (#1410)
• See (e1cbde5) https://snakemake.readthedocs.io/en/stable/snakefiles/rules.html#template-rendering-integration