Blockdev table for linux

Looks like this
```
osquery> select * from block_devices;

+------------+----------+----------+------------------+----------+--------------------------------------+------+-------+
| name       | parent   | vendor   | model            | size     | uuid                                 | type | label |
+------------+----------+----------+------------------+----------+--------------------------------------+------+-------+
| /dev/sr0   |          | QEMU     | QEMU DVD-ROM     | 2097151  |                                      |      |       |
| /dev/vda   |          |          |                  | 41943040 |                                      |      |       |
| /dev/vda1  | /dev/vda |          |                  | 41938944 | e9d1be20-80ec-43f5-83b6-90d8f10f93f5 | ext4 |       |
| /dev/loop0 |          |          |                  | 0        |                                      |      |       |
| /dev/loop1 |          |          |                  | 0        |                                      |      |       |
| /dev/loop2 |          |          |                  | 0        |                                      |      |       |
| /dev/loop3 |          |          |                  | 0        |                                      |      |       |
| /dev/loop4 |          |          |                  | 0        |                                      |      |       |
| /dev/loop5 |          |          |                  | 0        |                                      |      |       |
| /dev/loop6 |          |          |                  | 0        |                                      |      |       |
| /dev/loop7 |          |          |                  | 0        |                                      |      |       |
| /dev/ram0  |          |          |                  | 131072   |                                      |      |       |
| /dev/ram1  |          |          |                  | 131072   |                                      |      |       |
| /dev/ram10 |          |          |                  | 131072   |                                      |      |       |
| /dev/ram11 |          |          |                  | 131072   |                                      |      |       |
| /dev/ram12 |          |          |                  | 131072   |                                      |      |       |
| /dev/ram13 |          |          |                  | 131072   |                                      |      |       |
| /dev/ram14 |          |          |                  | 131072   |                                      |      |       |
| /dev/ram15 |          |          |                  | 131072   |                                      |      |       |
| /dev/ram2  |          |          |                  | 131072   |                                      |      |       |
| /dev/ram3  |          |          |                  | 131072   |                                      |      |       |
| /dev/ram4  |          |          |                  | 131072   |                                      |      |       |
| /dev/ram5  |          |          |                  | 131072   |                                      |      |       |
| /dev/ram6  |          |          |                  | 131072   |                                      |      |       |
| /dev/ram7  |          |          |                  | 131072   |                                      |      |       |
| /dev/ram8  |          |          |                  | 131072   |                                      |      |       |
| /dev/ram9  |          |          |                  | 131072   |                                      |      |       |
+------------+----------+----------+------------------+----------+--------------------------------------+------+-------+
```
Can you trim these down so that there's no whitespace on the edges. That happens when you convert fixed length char*'s to std::string's. Check out https://github.com/facebook/osquery/blob/6dee18c29c989b0810a9bc9fa953dc7540f634a5/osquery/tables/system/darwin/kextstat.cpp#L52-L53 for an example.