Add new SVC_InfoString and SVC_Info hooks

[ShadowsAdi]

Add an engine hook in reAPI for SVC_InfoString : https://github.com/dreamstalker/rehlds/blob/master/rehlds/engine/sv_main.cpp#L2843 with ability to set Info_SetValueForKey with values for given key buffer.
And for SVC_Info: https://github.com/dreamstalker/rehlds/blob/master/rehlds/engine/sv_main.cpp#L2957 with ability to set given values by [set_]*[get_]key_value for certain packet bytes using bitsum.
( Examples )

enum(<<= 1)
{
	BIT_STRING = 1,
	BIT_LONG,
	BIT_SHORT,
	BIT_BYTE ,
}

public SVC_InfoString_Pre(szPointer[], szKey[], szBuffer[], iLen)
{
	(Some function same as set_key_value / get_key_value but with pointer to buffer as array, not int) 
	const hostname[] = "Tests"
	new iBuf = get_key_value("hostname")
	set_key_value(iBuf, hostname, sizeof(hostname))
}

public SVC_Info_Pre(iPointer, iKey, szBuffer[], iLen)
{
	(Some function same as set_key_value but with pointer to buffer as array, not int) 
	Something related to sizebuf_t struct to set buffers, I think.
	
	Same behaviour as SVC_InfoString but setting key values as they are: string, int, long, short, byte. iKey = bitsum value of the key value which will be sent (string, long, short, byte)

	set_key_value(iKey, hostname, sizeof(hostname), /* additional param */BIT_STRING)
	set_key_value(iKey, mod_version, _, /* additional param */ BIT_BYTE)
}

P.S. : I don't know if it's better to use NET_SendPacket hook or those, so, let me know and thanks for read.