Coarse MacVim version reporting in about, update checks and github releases #1293

Steps to reproduce

1. Look on the about dialog box and it shows "Custom version 9.0.472 (174)`. close it
2. Open Check for updates menu. it shows "MacVim 9.0.472 is the newest version"
3. Check GitHub releases page, it shows "MacVim Release 174"

Expected behaviour

I expect all sources show more or less the same text, e.g. "MacVim Release 9.0.472 (174)". This is required for a user to have a strong visual connection between versions seen in all of these sources

I do NOT expect that :version command is touched in any way.
I do NOT expect that HomeBrew/MacPorts versioning is touched in any way.

Version of Vim and architecture

arm64

Environment

Operating system: macOS Monterey 12.6
Terminal: GUI only

How MacVim was installed

from GitHub releases to the default location

Logs and stack traces

No response

Vim configuration where issue is reproducable

No response

Issue has been tested with given configuration

• by running MacVim.app from GUI macOS interface
• by running vim/gvim/etc installed by MacVim
• by running other versions of vim (e.g. /usr/bin/vim)

Issue has been tested with no configuration

• by running mvim --clean (or gvim, supplied by MacVim distribution)
• by running vim --clean (in terminal, supplied by MacVim distribution)
• by running vim --clean (in terminal, other suppliers, e.g. /usr/bin/vim)

Other conditions

• The both Homebrew packages "vim" and "macvim" are installed