Spanification tool: fix const qualifier of std::array<>

`const char* array[] = ... ;` must be rewritten into
`std::array<const char*, ...> array = ...;`

However the `const` is not included by clang::ArrayTypeLoc,
we have to use clang::VarDecl::getSourceRange().

This CL also fixes GetTypeString() and makes it to generate
`clang::ElaboratedType` keyword. So we don't need to
use `getRewrittenText()` to get `uint8_t', and so on.

Bug: 359754054
Change-Id: I0c7c1c12ece9f2e617fd410ddbeb4bc467135cf6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5872258
Reviewed-by: Arthur Sonzogni <arthursonzogni@chromium.org>
Commit-Queue: Takashi Sakamoto <tasak@google.com>
Cr-Commit-Position: refs/heads/main@{#1359161}