[config] Checker label fixes and 6.29 profile update

[gamesh411]

Removed checkers from the default profile that are too noisy according
to our labeling criteria in
scripts/llm-scripts/checker_labeling_instructions.md, and the noisiest
of those from sensitive as well.
security.insecureAPI.strcpy goes the other way and gains sensitive,
which is the band its report count puts it in.

clang-diagnostic-format-nonliteral is held in default despite crossing
the 30x median threshold. Nearly all of its new reports are the vim
gettext idiom, and the high number of reports seems to be a result of a
clang regression around __attribute__((format_arg)), so the count is not
representative.

clang renamed alpha.unix.cstring.UninitializedRead to
unix.cstring.UninitializedRead since the last release. Add an entry for
the new name, and give the alpha one the same EXP33-C mapping, since we
still support the clang versions that only have it.

Three misspellings left the affected checkers without a severity and
outside the CWE Top 25 guideline, with nothing to signal it: a
misspelled key is silently ignored, and so is a guideline name that
descriptions.json does not define.

alpha.cplusplus.MisusedMovedObject carried only a doc url. It is the
pre-rename name of cplusplus.Move, and we still support the clang
versions that only have the old name, so it takes that entry's mapping.
cplusplus. Move itself had no doc url at all, so it gets one.

alpha.core.StdVariant also carried only a doc url. Retrieving an
inactive alternative with std::get throws std::bad_variant_access, so a
true positive means the code will fail at run time, which is HIGH by the
descriptions.json definition.

cppcheck-redundantContinue was in default but in neither sensitive nor
extreme. The profiles are nested by definition.

Eighteen checkers new in clang-tidy and cppcheck had no entry at all,
added those as well.