MM-53814 - Updating contrast for accessibility (#24381)

* Updating contrast for accessiblity

* Updating accessbility

* Updating accessiblity for icons

* Updating header icons

* Updating text opacity

* Updating icons and text

* Updating sidebar left

* Upadating icon in system console

* Updating global header

* Updating channel list

* Updating tests and fixing conflicts

* Updating filter css

* Updating css

* Updating epehemeral message contrast

* Updating icon with 64 opacity

* Updating test

* Updating confirm license removal csss

* Updating unintended files

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Co-authored-by: Mattermost Build <build@mattermost.com>

webapp/channels/src/components/cloud_start_trial/request_business_email_modal.scss

@@ -23,7 +23,7 @@
             &:focus,
             &:active:focus {
                 background-color: rgba(var(--center-channel-color-rgb), 0.08);
-                color: rgba(var(--center-channel-color-rgb), 0.72);
+                color: rgba(var(--center-channel-color-rgb), 0.8);
                 opacity: 1;
             }
 
@@ -32,7 +32,7 @@
             width: 4rem;
             height: 4rem;
             border-radius: 4px;
-            color: rgba(var(--center-channel-color-rgb), 0.56) !important;
+            color: rgba(var(--center-channel-color-rgb), 0.75) !important;
             font-family:
                 'Open Sans',
                 sans-serif;