* [#MM-12410] Custom Terms of Service Modal.
- Create a new screen for terms of service
- Register it in app navigation
- Open it as a modal when login succeeds or app is opened when already logged in.
- Get terms of service and render it as markdown
* Refactor service terms to terms of service
* Show terms modal when launching channel instead of componentDidMount
* Remove footer text
* Close modal before logging out
* Use dismissAllModals instead od this.close
* Update header styles
* Update the back icon
* Add left icon conditinally based on os
* Update en.json
* - Integrate Accept/Reject API
- Refactor show navigator to util
- Remove title
- Code refactoring
* Handle Accept/Reject API errors
* Update package-lock
* - Show Alert to handle API error
- Handle API error for GetTerms error, Accept/Reject error and Reject success
- Changes in en.json
- Remove error banner
- Open terms modal in sso and experimental certificate
* Enable navigator buttons after getting terms
* Rename Ok to OK in Alert
* Add retry for API error
* Fix check-style
* Fix FailedNetworkAction Error Message
* - Use Close button instead of back button
- Update en.json
* Remove unused import
* Disable hashtags and atmentions in terms modal
* Enable close button when terms text fails to load
* Minor changes
* Fix show terms on sso login
* Handle restartApp event
* Add test cases
* Revert change to app/components/formatted_markdown_text.js
* Show the terms modal on the channel page
* Remove remaining references to showTermsOfService
* Disable Hashtags, AtMentions and ChannelLinks
* Update the props to markdown component
* Pass the text as literal to renderText
* Return the generated renderTexts
* Fix lint
* Render ~, #, @ with Channel link, Hashtags and At Mentions
* Fix failing tests
Revert unwanted changes
* Hide the channel page content before the terms are accepted
* Fix lint and failing tests
* Revert changes to hide channel while terms are not accepted
* Open modal in componentDidMount instead of constructor
Code refactoring
Disable back button on android
* Remove unused import
* No need to await for showModal
* No need to await for accept and reject
* Update flag for updateTermsOfServiceStatus to updateMyTermsOfServiceStatus
- as phase 2 redux PR was mered.
* Fix check-style
* Change opacity in terms of service text
- Fix tests
* Revert package-lock.json changes
* MM-12901 Create showSearchModal action and use for hashtags
* MM-12901 Improve handling of hashtags on Recent Mentions, Flagged Posts, and Permalink screens
* MM-10273 Add hashtag support
* Put hashtag search in a proper modal
* Change hashtag search style to match regular search
* Move Hashtag component and explicitly pass props
* Add unit tests for Hashtag component
* Fix merge conflict
* Long post support
* Fix upload preview
* Add MaxPostSize validation
* Fix show more button container
* localization
* feedback review
* UI feedback review
* Upgrade mattermost-redux
* Fix long post attachment list
