More typed arrays in the FrameTable (and a flags column) - #6173

So far, the columns we've converted to typed arrays were either
always non-empty, or they used -1 as the "no value" sentinel.
For the FrameTable, I've opted to not to use -1 sentinel values,
and instead have a flags column with a "HasXYZ" flag for each column
(e.g. FrameFlags.HasAddress), for the following reasons:
- I'd like to use U8 and U16 arrays for the category and subcategory
  columns. That's already what we use in the derived StackTable.
  With an external flag we can go up to 256 subcategories without
  having to use 16 bits.
- I'm changing the inlineDepth column into just a "is inline" bool.
  This is a good fit for a flag.
- The address column was using -1 as the "no address" sentinel; having
  the flag lets us use U32 instead of I32 for the address column and
  have relative addresses for 4GiB binaries rather than just 2GiB.

An alternative I considered (but discarded) was to have a bitset for
each column. E.g. one "isInlined" bitset where, in the JSON, each item
is a U8 with the bits for 8 different frames. And similarly we could
have a "hasCategory" bitset. But that was too many extra columns in my
opinion.