feat(cli): Add --os-microversion-strategy flag

[gtema]

Exposes a global --os-microversion-strategy floor|ceiling flag
(OS_MICROVERSION_STRATEGY env var) so users can opt into requesting
the highest compatible microversion instead of the historical
lowest-compatible default. Wires through to
AsyncOpenStack::builder(...).microversion_strategy(...), which now
consistently drives both the request header and generated dispatch
schema selection via resolve_microversion. Default stays Floor to
preserve existing behavior.

Signed-off-by: Artem Goncharov artem.goncharov@gmail.com

[garloff]

Thanks, Artem! It sort of works ...

garloff@dev2018(:art-ucs):/casa/src/OpenStack/openstack [0]$ ./target/release/osc compute server list
┌──────────────────────────────────────┬────────────┬────────┬──────────────────────┬───────┬────────┬─────────────────────────────────┐
│ id                                   ┆ name       ┆ status ┆ created              ┆ image ┆ flavor ┆ security_groups                 │
╞══════════════════════════════════════╪════════════╪════════╪══════════════════════╪═══════╪════════╪═════════════════════════════════╡
│ 236fe824-0f66-47f0-86dd-0023aef1252a ┆ SCS_UCS_NC ┆ ACTIVE ┆ 2025-01-17T22:41:23Z ┆ null  ┆ null   ┆ [{"name":"SSH"},{"name":"HTTP"} │
│                                      ┆            ┆        ┆                      ┆       ┆        ┆ ,{"name":"ICMP"},{"name":"HTTPS │
│                                      ┆            ┆        ┆                      ┆       ┆        ┆ "},{"name":"SMTP"},{"name":"def │
│                                      ┆            ┆        ┆                      ┆       ┆        ┆ ault"}]                         │
│ bff06941-8a5d-4b68-948e-fcd66aa71696 ┆ OS156      ┆ ACTIVE ┆ 2025-01-17T16:11:21Z ┆ null  ┆ null   ┆ [{"name":"SSH"},{"name":"defaul │
│                                      ┆            ┆        ┆                      ┆       ┆        ┆ t"}]                            │
└──────────────────────────────────────┴────────────┴────────┴──────────────────────┴───────┴────────┴─────────────────────────────────┘
garloff@dev2018(:art-ucs):/casa/src/OpenStack/openstack [0]$ ./target/release/osc compute server list --os-microversion-strategy ceil
error: invalid value 'ceil' for '--os-microversion-strategy <OS_MICROVERSION_STRATEGY>'
  [possible values: floor, ceiling]

  tip: a similar value exists: 'ceiling'

For more information, try '--help'.
garloff@dev2018(:art-ucs):/casa/src/OpenStack/openstack [2]$ ./target/release/osc compute server list --os-microversion-strategy ceiling┌──────────────────────────────────────┬────────┬──────────────────────┐
│ id                                   ┆ status ┆ created              │
╞══════════════════════════════════════╪════════╪══════════════════════╡
│ 236fe824-0f66-47f0-86dd-0023aef1252a ┆ ACTIVE ┆ 2025-01-17T22:41:23Z │
│ bff06941-8a5d-4b68-948e-fcd66aa71696 ┆ ACTIVE ┆ 2025-01-17T16:11:21Z │
└──────────────────────────────────────┴────────┴──────────────────────┘

Maybe I now better understand why you default to the lowest microversion -- the list of output fields matches it.
Let me see whether I can come up with a template that is good for current OpenStack ...
Sidenote: 0.13.3 did somehow succeed in displaying flavor names.