XSS mitigation features (#4041)

* Remove HtmlPurifier calls

- All calls to Services::htmlPurifier()->purify() removed from data received from view.
- Bootstrap and bootswatch bump in package-lock.json

Signed-off-by: objecttothis <objecttothis@gmail.com>

* Pre-view filtering Items Controller

- Refactored code for clarity
- Created and called sanitization functions.
- Sanitize TEXT type Attributes before being sent to the view.

Signed-off-by: objecttothis <objecttothis@gmail.com>

* Pre-view filtering Customers Controller

- Refactored code for clarity
- Replaced == with === operator to prevent type juggling
- Added Sanitization of Customer data before being sent to the view

Signed-off-by: objecttothis <objecttothis@gmail.com>

* Bump bootstrap-table to 1.23.1

- Bump bootstrap-table to 1.23.1 in attempt to resolve issue with sticky headers
- Sanitize attribute data in tables
- Sanitize item data with controller function.

Signed-off-by: objecttothis <objecttothis@gmail.com>

* Pre-view filtering Items Controller

- Refactored code for clarity
- Created and called sanitization functions.
- Sanitize TEXT type Attributes before being sent to the view.

Signed-off-by: objecttothis <objecttothis@gmail.com>

* Sanitize Item data

- Sanitize category and item_number before display in forms.
- refactor check in pic_filename for empty to be best practices compliant.
- Added TODO

Signed-off-by: objecttothis <objecttothis@gmail.com>

* Minor changes

- Refactored for code clarity.
- Removed extra blank lines.
- Minor reformatting.
- Added PHPdocs
- bumped bootstrap-table to 1.23.2

Signed-off-by: objecttothis <objecttothis@gmail.com>

* Pre-view filtering Items Controller

- Refactored code for clarity
- Created and called sanitization functions.
- Sanitize TEXT type Attributes before being sent to the view.

Signed-off-by: objecttothis <objecttothis@gmail.com>

* Sanitize Item data

- Sanitize category and item_number before display in forms.
- refactor check in pic_filename for empty to be best practices compliant.
- Added TODO

Signed-off-by: objecttothis <objecttothis@gmail.com>

---------

Signed-off-by: objecttothis <objecttothis@gmail.com>
Co-authored-by: objecttothis <objecttothis@gmail.com>

app/Controllers/Sales.php

@@ -186,7 +186,7 @@ class Sales extends Secure_Controller
 	{
 		$suggestions = [];
 		$receipt = $search = $this->request->getGet('term') != ''
-			? Services::htmlPurifier()->purify($this->request->getGet('term'))
+			? $this->request->getGet('term')
 			: null;
 
 		if($this->sale_lib->get_mode() == 'return' && $this->sale->is_valid_receipt($receipt))
@@ -206,7 +206,7 @@ class Sales extends Secure_Controller
 	public function suggest_search(): void
 	{
 		$search = $this->request->getPost('term') != ''
-			? Services::htmlPurifier()->purify($this->request->getPost('term'))
+			? $this->request->getPost('term')
 			: null;
 
 		$suggestions = $this->sale->get_search_suggestions($search);