Add a new config "jdbc_drivers_dir" for both FE and BE.
User can put jdbc drivers' jar file in this dir, and only specify file name in "driver_url" properties
when creating jdbc resource.
And Doris will find jar files in this dir.
Also modify the logic so that when the jdbc resource is modified, the corresponding jdbc table
will get the latest properties.
1. solved the previous delayed unit test file size is too large (1.7G+) and the unit test link time is too long problem problems
2. Unify all unit tests into one file to significantly reduce unit test execution time to less than 3 mins
3. temporarily disable stream_load_test.cpp, metrics_action_test.cpp, load_channel_mgr_test.cpp because it will re-implement part of the code and affect other tests
This feature is propsoed in [DSIP-1](https://cwiki.apache.org/confluence/display/DORIS/DSIP-001%3A+Java+UDF).
This PR support fixed-length input and output Java UDF. Phase I in DIP-1 is done after this PR.
To support Java UDF effeciently, I use no data copy in JNI call and all compute operations are off-heap in Java.
To achieve that, I use a UdfExecutor instead.
For users, a UDF class must have a public evaluate method.
* update gcc to gcc 10 and support c++17
update brpc to 0.9.7
update boost to 1.73
remove third-party boost 1.54 for mysql
* update cmake version
* ignore jdk version
* remove unused patch
* avoid use SYS_getrandom call
Now Env has unify all environment operation, such as file operation.
However some of our old functions don't leverage it. This change unify
FileUtils::scan_dir to use Env's function.
* Add UserFunctionCache to cache UDF's library
This patch replace LibCache with UserFunctionCache. LibCache use HDFS
URL to identify a UDF's Library, and when BE process restart all of
downloaded library should be loaded another time. We use function id
corresponding to a library, and when process restart, all downloaded
libraries can be loaded without another downloading.
* update
