cmd: support type!=status in get --status-selector

`flux get --status-selector` only supported equality (`type=status`),
so finding objects that are not in a given state required multiple
invocations, e.g. listing everything that is not ready needed both
`Ready=False` and `Ready=Unknown`.

Add support for a negated selector `type!=status`. Since all resource
adapters delegate matching to the shared `statusMatches` helper and
filtering is centralised in `getRowsToPrint`, negation is implemented
purely in the parse/filter layer by inverting the match result. This
covers every resource type and the `--watch` path without touching the
per-resource adapters.

A missing condition is treated as not-matching by `statusMatches` (Flux
considers it "waiting to be reconciled"), so `Ready!=True` also surfaces
objects that have no Ready condition yet, i.e. the complete not-ready set:

    flux get all -A --status-selector Ready!=True

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Signed-off-by: 3uzbcqje <3uzbcqje@addy.to>

cmd/flux/testdata/get/get_status_ready_false.golden

@@ -0,0 +1,2 @@
+NAME     	REVISION	SUSPENDED	READY	MESSAGE                                   
+gr-failed	        	False    	False	failed to checkout and determine revision	

cmd/flux/testdata/get/get_status_ready_not_true.golden

@@ -0,0 +1,3 @@
+NAME      	REVISION	SUSPENDED	READY  	MESSAGE                                   
+gr-failed 	        	False    	False  	failed to checkout and determine revision	
+gr-unknown	        	False    	Unknown	reconciliation in progress               	

cmd/flux/testdata/get/get_status_ready_true.golden

@@ -0,0 +1,2 @@
+NAME    	REVISION          	SUSPENDED	READY	MESSAGE                              
+gr-ready	main@sha1:696f056d	False    	True 	Fetched revision: main@sha1:696f056d	

cmd/flux/testdata/get/status_objects.yaml

@@ -0,0 +1,71 @@
+---
+apiVersion: v1
+kind: Namespace
+metadata:
+  name: {{ .fluxns }}
+---
+apiVersion: source.toolkit.fluxcd.io/v1
+kind: GitRepository
+metadata:
+  name: gr-failed
+  namespace: {{ .fluxns }}
+spec:
+  ref:
+    branch: main
+  secretRef:
+    name: flux-system
+  url: ssh://git@github.com/example/repo
+  interval: 5m
+status:
+  conditions:
+    - lastTransitionTime: "2021-07-20T00:48:16Z"
+      message: 'failed to checkout and determine revision'
+      reason: GitOperationFailed
+      status: "False"
+      type: Ready
+---
+apiVersion: source.toolkit.fluxcd.io/v1
+kind: GitRepository
+metadata:
+  name: gr-ready
+  namespace: {{ .fluxns }}
+spec:
+  ref:
+    branch: main
+  secretRef:
+    name: flux-system
+  url: ssh://git@github.com/example/repo
+  interval: 5m
+status:
+  artifact:
+    lastUpdateTime: "2021-08-01T04:28:42Z"
+    revision: main@sha1:696f056df216eea4f9401adbee0ff744d4df390f
+    path: "example"
+    url: "example"
+    digest: sha1:696f056df216eea4f9401adbee0ff744d4df390f
+  conditions:
+    - lastTransitionTime: "2021-07-20T00:48:16Z"
+      message: 'Fetched revision: main@sha1:696f056df216eea4f9401adbee0ff744d4df390f'
+      reason: GitOperationSucceed
+      status: "True"
+      type: Ready
+---
+apiVersion: source.toolkit.fluxcd.io/v1
+kind: GitRepository
+metadata:
+  name: gr-unknown
+  namespace: {{ .fluxns }}
+spec:
+  ref:
+    branch: main
+  secretRef:
+    name: flux-system
+  url: ssh://git@github.com/example/repo
+  interval: 5m
+status:
+  conditions:
+    - lastTransitionTime: "2021-07-20T00:48:16Z"
+      message: 'reconciliation in progress'
+      reason: Progressing
+      status: "Unknown"
+      type: Ready