[MacPorts] #44946: Add method of showing installed & available versions of outdated ports at once

[MacPorts]

#44946: Add method of showing installed & available versions of outdated ports at
once
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 Reporter:  macports@…   |      Owner:  macports-tickets@…
     Type:  enhancement  |     Status:  new
 Priority:  Normal       |  Milestone:
Component:  base         |    Version:  2.3.1
 Keywords:               |       Port:
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 # port echo outdated
 # port installed outdated
 # port list outdated

 the first two show me the current installed versions of my outdated ports,
 the third shows me the available version that i could install

 if the set of outdated ports is short, it's easy to run both commands and
 compare, but its very hard to see what changes will actually happen with a
 long list

 i suspect there may be issues changing the default output format of either
 command (?) but would it be possible to add a way of optionally seeing
 both installed + available versions listed side by side?

 e.g. by having the installed or available ports shown in verbose mode for
 one/more of these commands (e.g. port -v list outdated), or by adding an
 option to one of the commands to show both installed + available versions
 (e.g. port list -v outdated)

 i've looked for other ways of 'joining' this information, and the closest
 i can find is port -y upgrade outdated, which is about 3x the output and
 much harder for human-parsing...

 this may also (slightly) overlap with #26028, at least in terms of user-
 interest if not functionality

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Ticket URL: <https://trac.macports.org/ticket/44946>
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