colexecbase: add more casts from strings

This commit adds the native cast from strings to ints, floats, and
timestamps. I was inspired to do this because the combination of this
commit and the vectorized rendering on top of the wrapped row-by-row
processors would expose some bugs (e.g. #83094).

Release note: None

pkg/sql/colexec/colexecbase/BUILD.bazel

@@ -34,6 +34,7 @@ go_library(
         "//pkg/util/duration",  # keep
         "//pkg/util/json",  # keep
         "//pkg/util/log",
+        "//pkg/util/timeutil/pgdate",  # keep
         "//pkg/util/uuid",  # keep
         "@com_github_cockroachdb_apd_v3//:apd",  # keep
         "@com_github_cockroachdb_errors//:errors",