PLT-4404/PLT-4578/PLT-4541/PLT-4542 Replaced third party autosizing textarea with a custom one (#4442)

* PLT-4578 Replaced third party autosizing textarea with a custom one

* Fix Textbox.handleHeightChange not being called

* Removed unused CSS

* PLT-4541 Force EditPostModal to resize upon opening

* Removed usage of jquery from AutosizeTextarea

* Reverted changes made for PLT-4580 as they're no longer needed

NOTICE.txt

@@ -1284,37 +1284,6 @@ limitations under the License.
 
 ---
 
-This product contains a modified portion of 'react-autosize-textarea', a light replacement for built-in textarea component which automaticaly adjusts its height to match the content.
-
-* HOMEPAGE: 
-  * https://github.com/buildo/react-autosize-textarea
-  
-* LICENSE: 
-
-The MIT License (MIT)
-
-Copyright (c) 2016 buildo s.r.l.s.
-
-Permission is hereby granted, free of charge, to any person obtaining a copy
-of this software and associated documentation files (the "Software"), to deal
-in the Software without restriction, including without limitation the rights
-to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-copies of the Software, and to permit persons to whom the Software is
-furnished to do so, subject to the following conditions:
-
-The above copyright notice and this permission notice shall be included in all
-copies or substantial portions of the Software.
-
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-SOFTWARE.
-
----
-
 This product contains a modified portion of 'compass-mixins', which pulls SASS style sheets on Bower, and enjoys the compass mixins by using libsass for faster compilation, by Christopher M. Eppstein.
 
 * HOMEPAGE: