Added ALTER operations to set and remove table properties

[g-saransh]

GitHub issue link:

Problem:

Solution:

Testing:

• Unit tests
• Additional tests (add results below)

Documentation:

• Documentation not needed
• Updated README file
• Documentation prepared (provide link below)

[rafoid]

I suggest spelling out the operations names:

Suggested change

	* The property changes are expected in the following format:
	* SETTING key/value property
	* {
	* "set_prop":[
	* {"key":"p1","value":"v1"}
	* ]
	* }
	* REMOVING property key
	* {
	* "rm_prop":["p1","p2"]
	* }
	* The property changes are expected in the following format:
	* SETTING key/value property
	* {
	* "set_property":[
	* {"key":"p1","value":"v1"}
	* ]
	* }
	* REMOVING property key
	* {
	* "remove_property":["p1","p2"]
	* }

[rafoid]

Commit should be after your check of whether we altered anything. Otherwise, if some other operations were specified (or mistyped) you might get an exception that nothing was really committed.

[rafoid]

Can we update table properties within the same ALTER as schema update? If yes, this commit should go below the if (op == OP_NONE) check. Also if yes, check for DROP explicitly as above.