Uses ndx-mies extensions incorrectly

[t-b]

The current ndx-MIES extension with version 0.1.0 defines the main type MIESMetaData which inherits from LabMetaData. And this requires that all additional entries are placed in /general/$name where $name has MIESMetaData neurodata type.

The fallout from this bug is that the current version of ndx-mies can not be used for reading the special MIES metadata using pynwb. Our MIES datasets and groups are not even checked with pynwb's validation.

See also t-b/ndx-MIES#6.

Possibe solution:

• Move our MIES special stuff from /general/* to /general/MIES
• raise ndx-MIES extension version
• test ndx-MIES with NWBv2 files from MIES
• tell our consumers that the location has changed
• adapt MIES for the new location a well