Lint diagnostic tweaks needed

[a-frantz]

• message in this diagnostic is too long:

  wdl/wdl-lint/src/rules/nonmatching_output.rs

  Line 78 in 7802c28

  fn non_object_meta_outputs(span: Span, item_name: &str, ty: &str) -> Diagnostic {

• silence BlankLinesBetweenElements during version statement processing:

  wdl/wdl-lint/tests/lints/missing-blank-line-after-version/source.wdl

  Lines 4 to 5 in 7802c28

  	## TODO: this emits two errors, one from VersionFormatting and one from
  	## BlankLinesBetweenElements. Only one of the errors is expected.

• silence CommentWhitespace during the preamble:

  wdl/wdl-lint/tests/lints/missing-comment-space/source.wdl

  Lines 5 to 6 in 7802c28

  	## TODO: Line1 creates two diagnostics, one for CommentWhitespace and
  	## one for PreambleFormatting. Only one of the errors is expected.

  AND

  wdl/wdl-lint/tests/lints/preamble-ws/source.wdl

  Line 3 in 7802c28

  ## TODO: "Extra" diagnostic from CommentWhitespace should be addressed.

• MissingRequirements fires two diagnostics when runtime is used in v1.2 documents (it should only fire one):

  wdl/wdl-lint/tests/lints/missing-requirements-block/source.wdl

  Line 24 in 7802c28

  # TODO: This emits two diagnostics but should only emit one.

  AND

  wdl/wdl-lint/tests/lints/runtime-keys-wdl-1.2/source.wdl

  Line 1 in 7802c28

  ## TODO: A strange one: this emits two errors, both from MissingRequiremnts.

• Silence VersionFormatting if there's nothing in the document after the version statement:

  wdl/wdl-lint/tests/lints/one-line-after-version/source.wdl

  Line 6 in 7802c28

  ## TODO: There is an "extra" daignostic emitted. Fix this.

• No explanation for this one as I haven't investigated:

  wdl/wdl-lint/tests/lints/trailing-comma/source.wdl

  Line 4 in 7802c28

  ## TODO: line 110 is not emitting a BlankLinesBetweenElements error. This is a bug.