[code-reflection] RFR: Initializers through arguments [v3]

[Adam Sotona]

> Initializers through arguments implementation.
> This PR is chained to ongoing work on `If` and `Loop` due to conflicting changes in `OnnxProtoBuilder`.
> 
> Input image reshape has to be removed from the CNN model due to unexpected exceptions in `Conv` op in relation with initializers.

Adam Sotona has updated the pull request incrementally with one additional commit since the last revision:

  minor demo rearrangement

-------------

Changes:
  - all: https://git.openjdk.org/babylon/pull/340/files
  - new: https://git.openjdk.org/babylon/pull/340/files/a796b230..dbf678a3

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=babylon&pr=340&range=02
 - incr: https://webrevs.openjdk.org/?repo=babylon&pr=340&range=01-02

  Stats: 78 lines in 2 files changed: 51 ins; 26 del; 1 mod
  Patch: https://git.openjdk.org/babylon/pull/340.diff
  Fetch: git fetch https://git.openjdk.org/babylon.git pull/340/head:pull/340

PR: https://git.openjdk.org/babylon/pull/340