Hover

[psteinroe]

The poc of the hover create is simply searching for tables and shows the name of the table and, if set, the comment stored in the db. This is just the bare minimum to show that the infrastructure works, but there is still a lot left to mark this feature as complete:

• refactor the table resolver into the pg_type_resolver crate to share it with other crates that potentially need it
• support markdown in hover
• add more information to the hover content for tables, e.g. the create table statement or a table with all columns and their types
• add support for columns
• add support for functions
• add support for ...(add your request below)