[yang] add yang options for Context object (#10359)

#### Why I did it
Need to pass LY_CTX_DISABLE_SEARCHDIR_CWD to Context in order to disable automatically searching for schemas in current working directory (which is by default searched automatically)

#### How I did it
add additional attribute into YANG context

#### How to verify it
Create some invalid link on switch :
1) **ln -s /usr/abc xxx**
2) run **spm list**
--> There should not be these messages:
```
libyang[1]: Unable to get information about "xxx" file in "/tmp" when searching for (sub)modules (No such file or directory)
libyang[1]: Unable to get information about "xxx" file in "/tmp" when searching for (sub)modules (No such file or directory)
libyang[1]: Unable to get information about "xxx" file in "/tmp" when searching for (sub)modules (No such file or directory)
libyang[1]: Unable to get information about "xxx" file in "/tmp" when searching for (sub)modules (No such file or directory)
```

Author: ayurkiv-nvda

src/sonic-yang-mgmt/sonic_yang.py

@@ -12,7 +12,7 @@
 """
 class SonicYang(SonicYangExtMixin):
 
-    def __init__(self, yang_dir, debug=False, print_log_enabled=True):
+    def __init__(self, yang_dir, debug=False, print_log_enabled=True, sonic_yang_options=0):
         self.yang_dir = yang_dir
         self.ctx = None
         self.module = None
@@ -46,7 +46,7 @@ def __init__(self, yang_dir, debug=False, print_log_enabled=True):
         self.preProcessedYang = dict()
 
         try:
-            self.ctx = ly.Context(yang_dir)
+            self.ctx = ly.Context(yang_dir, sonic_yang_options)
         except Exception as e:
             self.fail(e)