Enhance filter parser

[yhabteab]

After all the testing we did last week, it turns out that the current implementation of the filter Parser is very buggy and sometimes crashes with very simple filter strings. This PR solves this by using goyacc generated Parser. This is similar to how we parse Icinga2 DSL with flex/bison. The grammar rules can be found in the parser.y file and you can find the Lexer and other parsing utils in the lexer.go file.

For local testing/debugging purposes you can re-build the parser with the following command.

go env -w GOBIN=/Users/yhabteab/go/bin
go install golang.org/x/tools/cmd/goyacc@latest
go generate './...'

This will also generate a parser.output file which contains all the parser states and is useful to resolve some shift/reduce conflicts.

[julianbrost]

However, I haven't pushed the auto-generated parser yet because it involves a lot of code changes that don't need to be reviewed, but when this PR is done, we can think about merging this parser here or auto-generating it every time when building noma, basically just like the Icinga2 *.ti files.

Have a look at go generate. Also, common practice in Go is to commit these files to the repo so that you don't have to bother with the these dependencies unless you actually want to change the parser.

[yhabteab]

fuzz: elapsed: 3m30s, execs: 1483038 (7807/sec), new interesting: 94 (total: 1558)
fuzz: elapsed: 3m33s, execs: 1507525 (8160/sec), new interesting: 94 (total: 1558)
fuzz: elapsed: 3m36s, execs: 1530168 (7550/sec), new interesting: 94 (total: 1558)
fuzz: elapsed: 3m39s, execs: 1553639 (7821/sec), new interesting: 94 (total: 1558)
fuzz: elapsed: 3m42s, execs: 1576623 (7661/sec), new interesting: 94 (total: 1558)
fuzz: elapsed: 3m45s, execs: 1595193 (6190/sec), new interesting: 95 (total: 1559)
fuzz: elapsed: 3m48s, execs: 1609919 (4910/sec), new interesting: 97 (total: 1561)
fuzz: elapsed: 3m51s, execs: 1630670 (6917/sec), new interesting: 99 (total: 1563)
fuzz: elapsed: 3m54s, execs: 1648763 (6029/sec), new interesting: 99 (total: 1563)
fuzz: elapsed: 3m57s, execs: 1667104 (6113/sec), new interesting: 99 (total: 1563)
fuzz: elapsed: 4m0s, execs: 1685923 (6255/sec), new interesting: 99 (total: 1563)
fuzz: elapsed: 4m3s, execs: 1704380 (6154/sec), new interesting: 99 (total: 1563)
fuzz: elapsed: 4m6s, execs: 1723764 (6479/sec), new interesting: 99 (total: 1563)
fuzz: elapsed: 4m9s, execs: 1744018 (6752/sec), new interesting: 99 (total: 1563)
fuzz: elapsed: 4m12s, execs: 1758080 (5418/sec), new interesting: 100 (total: 1564)
--- PASS: FuzzParser (251.66s)
PASS
ok  	github.com/icinga/noma/internal/filter	251.870s