Replace PACKAGE_VERSION & __DATE__ with release tag

[GalaxyShard]

Relevant: blocksds/sdk#196

For some reason, git describe seems to return the oldest of all the lightweight tags for any given commit on my machine, so commit 8113974d7f975e349c0e8f7d11b5c1e16e77a496 appears as v1.4.0-blocks instead of v1.5.0-blocks because they are the same commit. This could be fixed by using git's annotated tags, or partially fixed by having SDK_VERSION additionally defined in the top-level SDK Makefile since the SDK always has commits between versions.

[AntonioND]

The problem I have with this is that it's quite messy, and the only purpose is to have a different version string from the one we have right now. Also, this would be the only tool with this version string, which is strange.

Which version of git do you have? That behaviour is weird.

[GalaxyShard]

I'd imagine that if this PR were merged then the other tools should also be updated accordingly, since like you say, it would be inconsistent otherwise.

As for git...

$ git --version
git version 2.46.1

I think it may be caused by git not storing dates for lightweight tags; from man git-tag:

Tag objects (created with -a, -s, or -u) are called "annotated" tags; they contain a creation date, the tagger name and e-mail, a tagging
       message, and an optional GnuPG signature. Whereas a "lightweight" tag is simply a name for an object (usually a commit object).