Fix analysis_report crash on MISRA C++ results

generate_guideline_compliance_summary() renders the Guideline Compliance
Summary report by mapping each applied standard's short name to a display name
via the standard_pretty_name dict. That dict only contained entries for "cert"
and "autosar", so analyzing a database against the MISRA C++ pack
(codeql/misra-cpp-coding-standards) aborted the report generation with:

    KeyError: 'misra'

at the "**Coding Standards applied**" line (and the same lookup is used again
when tabulating per-guideline results). Add the missing "misra" ->
"MISRA C++:2023" mapping so MISRA C++ analyses can produce the compliance
summary report like the other supported standards.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: castler

scripts/reports/utils.py

@@ -183,7 +183,10 @@ def generate_guideline_compliance_summary(output_directory, results_summary):
                 print(
                     "**Result**: " + ("Not compliant" if total_guidelines_violated > 0 else "Compliant"))
                 standard_pretty_name = {
-                    "cert": "CERT C++ 2016", "autosar": "AUTOSAR C++  R22-11, R21-11, R20-11, R19-11 and R19-03"}
+                    "cert": "CERT C++ 2016",
+                    "autosar": "AUTOSAR C++  R22-11, R21-11, R20-11, R19-11 and R19-03",
+                    "misra": "MISRA C++:2023",
+                }
                 print("**Coding Standards applied**: " + ", ".join([standard_pretty_name[standard_short_name]
                       for standard_short_name in results_summary.guideline_violation_count.keys()]))