Allow for tags with whitespaces and special characters

[digitalsignalperson]

Here's an attempt to solve #29

I've tested

• see correct [read/unread] counts for tags like/this in the tag panel
• double clicking a tag in the tag panel correctly gives the search results for that tag
• the tag in the search query itself is excluded from the shows tags

Not tested:

• adding/removing tags
• command bar
• probably some other things I'm unfamiliar with since I haven't fully explored all the features in dodo yet. I'm mainly using as a read-only interface for now as I get used to things.

[digitalsignalperson]

oops this should be in util.py instead

[The-Compiler]

This seems wrong. Additional quotes actually passed to notmuch are only required when a shell is involved, but this isn't the case here. I'm pretty sure this would now add the tags with the quotes, like doing '+"foo bar"' in a shell. No such quotes are needed when not using shell=True, at least for notmuch tag.

[digitalsignalperson]

Thanks for the review. I'll have to test this out. What you say makes sense I could see it adding the double quotes to the tags themselves. Yet in search and tag view I definitely needed the double quotes for some parts. I can review the different cases and print what the actual commands being sent to notmuch are and if they work as expected.

As noted I still haven't tested adding/removing tags, just mainly search and tag view. Also furthering that in #31
so still some testing to do

[The-Compiler]

For a query, that's true - from what I understand, that uses Xapian query syntax, which needs literal quotes:

Phrase searches

A phrase surrounded with double quotes ("") matches documents containing that exact phrase. [...]

Searching within a free-text field

If the database has been indexed with prefixes on terms generated from certain free-text fields, you can set up a prefix map so that the user can search within those fields. For example author:dickens title:shop might find documents by dickens with shop in the title. You can also specify a prefix on a quoted phrase (e.g. author:"charles dickens") [...]

Compare that to shell usage, where notmuch tag '+foo bar' tag:test adds the tag foo bar to a message (passing the argument +foo bar to notmuch), but then to find it, notmuch search tag:"foo bar" won't work, you'll need notmuch search 'tag:"foo bar"' (passing a literal tag:"foo bar" to notmuch/Xapian).