Introduce implementation for FileType - #3608

…#1)

* Add threshold-driven inline vs self-reference storage for FILE values

Writers hand FILE payloads to FileValueWriter, which decides from a
configured threshold whether to keep the bytes inline or store them out
of line as a self-reference. Both forms describe the same logical bytes,
so content_type and checksum are written identically either way and
consumers see no difference beyond which fields are set.

The payload is written eagerly, while the record is being written and
before the row group's column chunks are flushed. This is what makes the
offset knowable in time: offset and size are ordinary column values, and
once a value reaches a column writer it is encoded into a buffered page
and cannot be revised, so a placeholder could not be patched up later.
Writing at that point also leaves each column chunk contiguous on disk,
which the read path relies on when coalescing chunks into range reads.

Along the way, per parquet-format#603:

- Key the self-reference AAD on the file offset rather than a synthetic
  per-chunk counter. The spec defines AAD suffix field 6 as the offset,
  and the counter was not recoverable from the file: nothing stores it,
  so a reader had to walk preceding values to rebuild it, defeating the
  offset-based design that lets a value be resolved on its own. The
  ordinal parameter is gone from five signatures as a result.
- Decompress into a dynamically sized buffer, supporting every codec.
  The previous stream-drain loop was broken for all codecs, not just
  unframed ones: NonBlockedDecompressorStream throws rather than
  returning -1 once its block is consumed.
- Enforce the 2 GiB encrypted-module limit on write, directing oversized
  values to external references.
- Require inline whenever offset is declared. uri is optional per value,
  so a uri+offset+size schema still permits self-references, and one
  emitted without an inline column chunk has no reference point to
  inherit compression and encryption from.

Tests cover threshold routing, offset-keyed AAD round-trips in both GCM
and CTR modes, tamper detection when an offset is altered, and payloads
spanning several buffer doublings across SNAPPY, GZIP, ZSTD and LZ4_RAW.

Co-authored-by: Isaac

* Fix ZSTD resolution, revert schema tightening, fix test imports

Verified the change by building and running the suites locally, which
turned up three things:

ZSTD self-references could not be resolved at all. ZstandardCodec
returns null from createDecompressor because it decompresses only
through its stream, so driving the Decompressor directly failed with
"Could not obtain a decompressor". Such codecs are framed and report
end-of-input properly, so drain the stream for them and keep
grow-and-retry for the rest. Four tests were failing on this.

Reverted requiring `inline` whenever `offset` is declared, back to
requiring it only when `uri` is absent. Two existing tests
(testFileLogicalTypeExternalRangedReferenceWithoutInline,
testFileLogicalTypeOffsetWithSize) assert that a uri+offset+size schema
without `inline` is valid, so the stricter rule contradicted the
author's documented intent. The concern is real -- `uri` is optional per
value, so such a schema can still emit a self-reference with no
reference point -- but it belongs on the write path, and the FILE group
declaring `uri` is now documented as needing an always-inline threshold.

Fixed two pre-existing test compile errors that blocked the module:
TestParquetMetadataConverter used assertEquals/assertTrue with no JUnit
import (switched to the AssertJ style used throughout that file), and
TestSelfReferenceFileWrite was missing the ParquetReadOptions import.
Both fail on the base commit independently of these changes.

Also applied spotless formatting.

Local results: parquet-column 679/679 pass, parquet-hadoop 761/762. The
one failure, testEnumEquivalence on Encoding.ALP, is an artifact of the
local workaround for FileType being unreleased -- parquet.thrift was
substituted from parquet-format master, which defines an ALP encoding
the Java enum does not yet have. It is unrelated to these changes and
will not occur once a parquet-format release carries FileType.

Co-authored-by: Isaac